cogged joint A carpentry joint formed by two crossed structural timbers, each of which is notched at the place where they cross.

cogged joint

cogging, cocking The joining of two timbers which are notched, cogged, or indented.

cohesion 1. The molecular forces of attraction by which the body of an adhesive or sealant is held together; the internal strength of an adhesive or a sealant. 2. Of soil particles, the sticking together of particles whose forces of attraction exceed the forces that tend to separate them.

cohesionless soil A soil which when unconfined has no significant cohesion when submerged, and no significant strength when air-dried.

cohesive failure The tearing apart of a sealant as the joint expands if its adhesive (bond) capabilities exceed its cohesive capabilities.

cohesive soil 1. A soil which when unconfined has appreciable cohesion when submerged, and considerable strength when air-dried. 2. Soil, such as clay, whose particles adhere to each other by means of adhesive and cohesive forces.

coign See quoin.

coil A heat exchanger in the form of pipe or tubing in any of various configurations; fins may be attached to dissipate heat; also called an attemperator.

coiled expansion loop Same as expansion bend.

coin, quoin 1. The corner of a building. 2. The stones or bricks which form the corner. 3. A wedge.

coke grating A special grating fitted into an ordinary fireplace to burn No. 3 grade coke, ½ to 1¼ in. (1.3 to 3.1 cm) size, generally fitted with an integral gas burner to facilitate lighting of fuel.

COL On drawings, abbr. for column.

colarin Same as collarino.

cold-air return In an air-conditioning system in a house of wood frame construction, a return air duct which utilizes the space between joists.

cold-air return

cold bending, cold gagging The bending of metal without the application of heat, as the bending of metal pipe.

cold bridge Any type of break in a continuous thermal insulation barrier, leaving an opening that “short-circuits” the thermal insulation.

cold-cathode lamp An electric-discharge lamp which produces light by means of a glow discharge; operates at relatively low current and high voltage; has cylindrical electrodes which operate at a low temperature.

cold cellar Part of a cellar where root crops are stored during the winter at cold, but above-freezing, temperatures.

cold check The formation of fine cracks in wood finishes when subjected to cycles of heat and cold.

cold chisel A chisel with a cutting edge formed of tempered steel; used for cutting metal which has not been softened by heating.

cold chisel

cold cut, cold cutter A cold chisel mounted on a handle like a hammer; struck with a maul.

cold-drawn Descriptive of metal which has been drawn through a set of dies designed to reduce its cross-sectional area without heating the metal. The process is used in the fabrication of rod, tubing, and wire.

cold-driven rivet A rivet that is driven cold, without preheating.

cold-finished bar A metal bar, brought to its final dimensions by cold-working, which results in improved surface finish and dimensional tolerance.

cold-finished steel Carbon steel which has been cleaned and pickled and then rolled or drawn through dies to produce a dimensionally accurate section with an improved surface finish (and often with other improved properties).

cold flow 1. The permanent deformation of a material under constant stress. 2. At room temperature, the continuing dimensional change under static load that follows initial instantaneous deformation.

cold forging The forging of metal without the application of heat.

cold-formed member A structural steel member formed without the application of heat.

cold-formed steel construction That type of construction made up entirely, or in part, of steel structural members cold-formed to shape from sheet or strip steel, such as roof deck, floor and wall panels, floor joists, studs, roof joists, or other structural elements.

cold gagging See cold bending.

cold glue A glue which is a cold-setting adhesive.

cold joint A joint formed when a concrete surface hardens before the next batch of concrete is placed against it; characterized by a poor bond unless special procedures are observed.

cold-laid mixture Any mixture which may be spread and compacted at normal atmospheric temperature.

cold mix Asphaltic concrete for placement without heat; prepared with a relatively light and slow-curing asphalt; hardens to a state less firm and durable than hot-mixed asphaltic concrete.

cold molding 1. A procedure in which a composition is shaped at room temperature and cured by subsequent baking. 2. The material used in this procedure.

cold patch An application of asphaltic cold mix over a small area.

cold pie Mortar in excess of that actually used in laying a masonry unit.

cold pressing The bonding of components by pressure without the application of heat.

cold-process roofing A bituminous roofing membrane which consists of layers of coated felts that have been bonded with cold-applied asphalt roof cement and surfaced with an emulsified or cutback asphalt roof coating. Also see asphalt prepared roofing.

cold riveting Driving rivets cold, without preheating.

cold-rolled Descriptive of metal that has been formed by rolling at room temperature, usually to obtain improved surface finish or higher tensile strength.

cold room A room where low temperatures are maintained; a refrigeration room.

cold saw A saw for cutting metal at ordinary room temperatures, as a metal-cutting circular saw.

cold set A type of short steel chisel having a flat edge; used in cutting bars, flattening sheet-metal seams, etc.

cold-setting adhesive An adhesive that sets at temperatures below 68°F (20°C).

cold-shortness Brittleness in metal at room temperatures.

cold shut In a casting, a defect having the appearance of a fold or wrinkle.

cold-solder To solder without the application of heat, as with copper amalgam.

cold solder joint A faulty joint in electric wiring which results from the application of insufficient heat at the joint; the solder merely covers the joint and is not physically united with it.

cold-start lamp Same as instant-start fluorescent lamp.

cold-storage cooler An insulated room which is artificially cooled but whose temperature is never below 30°F (−1.1°C).

cold-storage door A heavy, thermally insulated door, fully gasketed at the frame; used on refrigerators and freezers.

cold strength Of refractory concrete, the compressive or flexural strength determined prior to firing.

cold-water paint A mixture of pigment and binder dissolved or dispersed in cold water.

cold welding The joining of metals (such as aluminum) at room temperature by subjecting thoroughly cleaned metal surfaces to pressure; coalescence is produced solely by the application of mechanical force.

cold-worked steel Descriptive of steel which has been rolled, drawn, or twisted at normal ambient temperatures; used for steel bars and wire in reinforcement for concrete.

cold working The plastic deformation of metal at or near room temperature; this shaping is usually carried out by drawing, pressing, rolling, or stamping.

cold wrap A type of corrosion-proof tape which is wrapped around a pipe without the application of heat.

coliseum See colosseum.

collapse Mechanical failure of cells in wood, usually caused by abnormal or forced drying.

collar 1. A metal cap flashing for a vent pipe projecting above a roof deck. 2. A raised band which encircles a metal shaft, a wood dowel, or a wooden leg. 3. A raised section to reinforce a metal weld. 4. A collarino. 5. The reinforcing metal of a nonpressure thermit weld. 6. Same as escutcheon.

collar beam, spanpiece, sparpiece, top beam, wind beam A horizontal member which ties together (and stiffens) two opposite common rafters, usually at a point about halfway up the rafters in a collar beam roof.

collar beam

collar beam roof, collar roof A roof supported by rafters tied together by collar beams.

collar brace A structural member which reinforces a collar beam in medieval roof framing.

collared hole A hole of shallow depth, drilled into a material to prevent slippage of the bit when a deeper hole is drilled.

collaring 1. Pointing with cement mortar under the overhangs of tiles or slabs. 2. The drilling of a collared hole.

collarino 1. A necking, as on a classic Tuscan, Doric, or Ionic capital; also called a collar, 4. 2. An astragal.

collar joint 1. The joint between a roof rafter and a collar beam. 2. The vertical joint between masonry withes.

collar tie In wood roof construction, a timber which prevents the roof framing from changing its shape.

collected plants Plants that are gathered from sources other than a working nursery.

collecting safe area In an emergency, a safe area that receives occupants from the assembly space it serves, as well as from other safe areas.

collection hopper A cart with wheels used to funnel concrete into drop chutes and elephant trunks, which may or may not be attached; often used alone for placing concrete in shallow restricted areas.

collector See solar collector.

collector box In roof drainage, a transition piece between a downspout and gutter.

collector street One which functions as a feeder from an area of limited traffic to a major street or highway.

Collegiate Gothic A secular version of Gothic architecture, characteristic of the older colleges of Oxford and Cambridge. Adopted in the late 19th and early 20th centuries by a number of other colleges in other countries.

Collegiate Gothic

colloid A gelatinous substance so finely divided that it remains in suspension when dispersed in a liquid.

colloidal concrete Concrete whose aggregate is bound by colloidal grout.

colloidal grout A grout which has artificially induced cohesiveness or ability to retain the dispersed solid particles in suspension.

colloidal mixer A mixer designed to produce colloidal grout.

collusion A secret agreement for illegal or fraudulent purposes.

colluviarium In ancient Rome, an opening made at regular intervals in an aqueduct, for ventilation.

Cologne earth, Cologne brown A type of Vandyke brown made from roasted American clays which contain ochre and bituminous matter.

colombage Half-timber construction.

colonette, colonnette 1. A small column, usually decorative. 2. In medieval architecture, a thin round shaft to give a vertical line in elevation, or as an element in a compound pier.

Colonial architecture Architecture transplanted from the motherland to overseas colonies. For examples see American Colonial architecture, Dutch Colonial architecture, English Colonial architecture, French Colonial architecture, German Colonial architecture, Spanish Colonial architecture. Compare with Colonial Revival.

colonial casing A type of decorative, exposed trim molding.

colonial casing

Colonial joint Same as tooled joint.

colonial panel door A door having stiles, rails, and a mutin which form frames around recessed panels.

colonial panel door

Colonial Revival An architectural mode that reuses selected aspects of earlier colonial prototypes, especially from around 1870 onward. In the United States, when this term is used without reference to a country of origin (simply as Colonial Revival), it usually refers to American Colonial Revival, based on prototypes in the English colonies in America. Of these prototypes, the Georgian and the Federal style (Adam style) are the most widely imitated, giving rise to the terms Georgian Revival and Federal Revival (Adam Revival). Colonial Revival houses are usually the result of a rather free interpretation of their prototypes; they tend to be larger than, and may differ significantly from, the houses they seek to emulate, often exaggerating architectural details. For descriptions of other types of colonial revival architecture, see Dutch Colonial Revival, Chateauesque style, French Eclectic architecture, Spanish Colonial Revival, Mission Revival, Pueblo Revival. Also see Neo-Colonial architecture.

colonial siding Wide, square-edged siding boards used extensively in early American construction. Also see weatherboarding.

colonial siding

colonnade A number of columns arranged in order, at intervals called intercolumniation, supporting an entablature and usually one side of a roof.

colonnade

colonnette See colonette.

colophony See rosin.

color (perceived) That attribute of visual perception that can be described by names such as yellow, red, blue, etc., or some combination of such names. (of an object) A characteristic of the appearance of an object, surface, etc., distinct from its form, gloss, shape, size, or position; depends on the spectral composition of the incident light, on the spectral reflectance or transmittance of the object, and on the spectral response of the observer.

color chart A chart showing a systematic array of colors or their representations.

color code A system of colors adopted for identification of pipes, cables, wiring, or the like.

colored aggregate Sand, gravel, or other aggregate chosen for the coloration it can impart to concrete in an exposed-aggregate finish.

colored cement A cement to which color pigment has been added.

colored concrete 1. Concrete tinted during its mixing by colored cement or color pigments. 2. Hardened concrete which has been subjected to a colored wash.

colored finishes In plastering, finish coats containing colored aggregates or color pigments; the color is intimately mixed throughout.

color frame A metal frame at the front of a luminaire, used to support transparent colored material, esp. in spotlights and floodlights.

coloring pigment 1. See pigment. 2. See stainer.

color pigment 1. A natural or synthetic pigment or stainer, usually iron or chromium oxides, added to either mortar or block concrete. 2. See pigment, 1.

color rendering index (CRI) A measure of the closeness with which a light approximates daylight having the same color temperature.

color retention The ability of a paint or varnish film to retain its original color appearance and not fade with age or exposure to sunlight.

color selection log See finish and color selection log.

color temperature Of a light source, the absolute temperature at which a blackbody, 1 radiator must be operated to have a chromacity equal to that of the light source.

colossal column A column that is more than one story in height.

colossal order, giant order An order more than one story in height.

colossal pilaster A pilaster that extends the full height of a building containing two or more floors.

colosseum, coliseum 1. (cap.) The Flavian amphitheater in Rome. 2. Any large Roman amphitheater. 3. Now, any large sports arena, open or roofed.

colosseum, 1 showing seating and plan at various levels

colour See color.

columbage In French Vernacular architecture of Louisiana, timber-framed construction with diagonal bracing of the framework; the space between the structural timbers was usually filled with bousillage or pierrotage.

columbarium One or a series of niches, intended to receive human remains. (See illustration p. 232.)

columella Same as colonette.

column 1. In structures, a relatively long, slender structural compression member such as a post, pillar, or strut; usually vertical, supporting a load which acts in (or near) the direction of its longitudinal axis. 2. In classical architecture, a cylindrical support consisting of a base (except in Greek Doric), shaft, and capital; either monolithic or built up of drums the full diameter of the shaft. 3. A pillar standing alone as a monument. (See illustration p. 232.)

columna cochlis In ancient Rome, a column with a spiral staircase around its center line.

columbarium

column, 2 Tuscan order

columna rostrata Same as rostral column.

columna triumphalis See triumphal column.

column baseplate A horizontal plate beneath the bottom of a column; transmits and distributes the column load to the supporting material below the plate.

column cage An assembly of reinforcing bars and ties for use in constructing a reinforced concrete column.

column capital A mushroom-like enlargement of reinforced concrete, at the upper end of a column, designed and built to act as an integral unit with the column and the floor slab above so as to increase the shearing resistance.

column casing Any form of enclosure of a steel column which provides a prescribed fire rating, e.g., a boxed enclosure fabricated of a fire-rated material, such as gypsum board; also see caged beam.

column clamp A fastening device for a form for a concrete column, holding together the sides of the form.

column curve The graphical relationship between the axial strength of a column and its slenderness ratio.

column footing See footing.

column head Same as column capital.

columniation Systems of grouping columns in classical architecture. Also see intercolumniation.

column side In a form for a concrete column, one of the vertical panels.

column splice A splice which unites two columns.

column strip That portion of a flat slab, over the columns, which consists of the quarter panels on both sides of the column center line.

colymbethra In a Greek church, the room or font for administering baptism.

COM Abbr. for “customer’s own material.”

Com, Com. In the lumber industry, abbr. for “common.”

comb 1. Combing, 1. 2. A drag, 1. 3. Any tool used to produce combing, 2, 3.

COMB. On drawings, abbr. for “combination.”

comb board A saddle board having notches along its upper edge.

comb ceiling A ceiling that sags inwardly like a tent. Also called a camp ceiling or tent ceiling.

comb cut Same as plumb cut.

combed Same as dragged.

combed-finish tile Tile whose face surfaces are altered by more or less parallel scratches in manufacture to give increased bond for mortar, plaster, or stucco.

combed joint A finger joint.

comb-grained See edge-grained, quartersawn.

combination column A column in which a structural steel member, designed to carry part of the load, is encased in concrete of such quality and in such manner that the combination of steel and concrete will carry the total load.

combination door An exterior door having interchangeable screen and glass storm-panel inserts; provides a glazed storm door in winter and a screened door in summer.

combination faucet A device in which the flow of water from hot and cold water pipes is controlled and is drawn from a common spout.

combination faucet

combination fixture A fixture which combines one or more kitchen sinks and laundry trays in a single unit.

combination frame In light wood-frame buildings, a combination of a full frame and a balloon frame.

combination ladder A portable ladder which may be used as a stepladder, extension ladder, single ladder, or trestle ladder.

combination plane 1. A plane having interchangeable cutters for various applications in shaping. 2. A plane having a guide which can be changed from one side to the other, or adjusted vertically.

combination pliers Slip-joint pliers having serrated faces for gripping rounded surfaces such as pipe, together with blades for cutting wire.

combination pliers

combination sheet In roofing, a fiberglass felt integrally attached to kraft paper.

combination square An adjustable carpenter’s tool consisting of a steel rule which slides through an adjustable head; may be used as a try square, miter square, level, marking gauge, plumb, and straightedge.

combination square

combination stair A stair in which access to the first landing is provided by a supplementary service stair as well as the main flight.

combination stair

combination waste and vent system A special system of venting in which the waste piping is purposely oversized; intended as an economical means of providing adequate protection of fixture traps against loss of seal in extensive installations where the individual venting of fixture drains would be impractical or uneconomical; serves both as a waste pipe and vent pipe.

combination window 1. A window equipped with removable or interchangeable screen and glass sections that make it suitable for either summer or winter use. 2. A window having several types of sash.

combined aggregate A mixture of fine and coarse aggregate for a concrete.

combined-aggregate grading The particle-size distribution of a mixture of fine and coarse aggregates.

combined building drain A building drain that conveys the drainage of both sewage and storm water.

combined building sewer A sewer that receives both storm water and sewage.

combined dry-pipe/preaction system A fire sprinkler system which combines automatic sprinklers (i.e., sprinkler heads) attached to a piping system containing air under pressure controlled by a fire detection system installed in the same areas as the sprinklers. See dry-pipe sprinkler system and preaction sprinkler system.

combined footing A footing which supports more than one column load.

combined frame A doorframe having fixed panes of glass flanking one or both sides of the door.

combined load Two or more different types of loads (such as dead load, live load, or wind load) on a structure, occurring simultaneously.

combined sewer A sewer which carries both sanitary sewage and storm water.

combined stack A soil pipe that carries both soil and waste discharges.

combined stresses A stress state which cannot be represented by a single component of stress.

combing 1. In roofing, the topmost row of shingles which project above the ridge line; the uppermost ridge on a roof. 2. Using a comb or stiff bristle brush to create a pattern by pulling through freshly applied paint. See antiquing. 3. Scraping or smoothing a soft stone surface.

combplate The toothed portion of the stationary threshold plate at both ends of an escalator or moving walk, designed to mesh with the grooved surface of the moving steps or treadway.

combustibility The ease with which a material will burn when subject to heat.

combustible Capable of undergoing combustion in air, at pressures and temperatures that might occur during a fire in a building.

combustion Any chemical process that produces light and heat as either glow or flames.

combustion liquid A liquid having a flash point at or above 140°F (60°C) and below 200°F (93.4°C).

combwork In plasterwork, 1 or pargeting, descriptive of an exposed plaster surface that has had a tooth-like tool dragged across it before it hardens.

come-along A tool for spreading concrete, similar to a hoe; has a blade approx. 20 in. (50 cm) wide and 4 in. (10 cm) high.

comedor A dining room in a Spanish Colonial house.

comfort chart A chart which relates effective temperature, dry-bulb temperature, wet-bulb temperature, and air movement to human comfort; comfort zones are indicated on such a chart.

comfort station A building or part thereof where toilet and lavatory facilities are available for public use.

comfort zone In a heating, ventilating, and air-conditioning system, the range in temperature, humidity, and air movement that most of the building’s occupants consider to be comfortable.

commaunder Same as a blockhouse.

commercial bronze An alloy containing 90% copper, 10% zinc; so called because of its bronze color; esp. used in weatherstripping.

Commercial Italianate style See Italianate style.

commercial projected window A type of steel projected window; intended for commercial and industrial buildings which do not require interior trim or finishing around the window.

Commercial style A style of commercial architecture developed by the Chicago School, applied primarily to multistory office buildings and mercantile buildings constructed from about 1875 to 1930. Usually characterized by a tripartite scheme consisting of a base that is one to three stories high, a shaft many stories high; and a cap, usually one to three stories high that tops the structure; a flat roof; an overhanging cornice; unadorned fenestration, most often with large rectangular windows (for example, see Chicago window); bay windows with decorative spandrels, 1. Sometimes called Chicago Commercial style.

commercial tolerances The plus and/or minus allowances that are acceptable with a specified dimension.

Commission Internationale de l’Eclairage International Commission on Illumination. Abbr. CIE.

commode step One of two (or more) steps at the foot of a flight of stairs which have curved ends projecting beyond the newel and the string, 1.

common A large plot of grassy, fenced-in, publicly owned land, generally at or near the center of a village or town; in earlier eras, once shared by the townspeople as a pasture.

common alloy An alloy that does not increase in strength when heat-treated but may be strengthened by strain hardening.

common American bond Same as common bond.

common-and-cross bond A bond that is a combination of cross bond, which describes the masonry facing, and common bond which describes the backing.

common area An area either within a building or outside a building which is intended for use of all occupants of the building or a group of buildings, but not for the free use of the general public.

common ashlar A pick- or hammer-dressed block of stone.

common bond A pattern of brickwork in which every third, fifth, sixth, or seventh course consists of headers (i.e., bricks laid horizontally with their lengths perpendicular to the face of the wall), and the other courses consist of stretchers (i.e., bricks laid horizontally so that their lengths are parallel to the face of the wall). This pattern is widely used because it can be laid relatively quickly.

common bond

common brass, high brass An alloy containing 65% copper, 35% zinc; the most common of commercial wrought brasses.

common brick Same as building brick.

common dovetail, box dovetail, through dovetail A dovetail joint in which the end grain shows on both members.

common dovetail

common excavation The excavation of material that does not require blasting, such as earth, in contrast to the excavation of solid rock.

common ground See ground, 1.

common house 1. That part of a monastery in which a fire was kept for the monks during the winter. 2. A one-room cottage in Spanish Colonial architecture of Florida, primarily in the first half of the 18th century. Characterized by: whitewashed tabby walls, a hipped roof that was thatched with palmetto fronds; and a smoke hole at the ridge of the roof; also see Saint Augustine house.

common joist, bridging joist A joist on which floorboards are laid; neither supports nor is supported by another joist.

common lap Shingle roofing in which alternate courses are offset one-half the width of a shingle.

common lime Either hydrated lime or quicklime; used in plastering.

common nail A cut or wire low-carbon steel nail, having a slender plain shank and a medium diamond point; used in work where finish is unimportant, as in framing.

common path of travel That portion of exit access that the occupants are required to traverse before two separate and distinct paths of travel to two exits are available.

common pitch In a spiral stair, the pitch of the fliers above and below the winders.

common purlin In timber-framed construction, one of a number of horizontal timbers that are parallel to the ridge of the roof, and joined to the principal rafters into which they are seated. The upper surfaces of the common purlins and the principal rafters are in the same plane. Also see purlin.

common rafter In wood-frame construction, one of a number of slanting structural members (extending from the ridgeboard down to the eaves) that support the roof; these members are usually of the same size and evenly spaced along the length of the roof ridge.

common rafter

common return An electrical conductor which serves as the electrical return for more than one circuit.

common roof A roof supported only by common rafters, without purlins.

common room 1. A room or lounge for the informal use of all members of a college. 2. A room or lounge for the use of the patrons of an inn.

common vent See dual vent.

common wall See party wall.

communicating frame A double-rabbeted frame (with the rabbets on each side) prepared for two single-swing doors, one on each side of the frame, which open in opposite directions.

communion rail In a church, a low railing enclosing that part of an altar within which the communicants are provided with a place to kneel and receive Communion.

Communion table In Protestant churches, a table used instead of an altar in the Communion service.

community A group of people having common rights, privileges, or interests, or living in the same place under the same laws and regulations.

community center A building or group of public buildings for the social, cultural, and educational activities of a neighborhood or entire community.

community-facilities plan A graphic and written statement depicting a desirable pattern of public facilities (e.g., schools and parks) within an area, including their character, location, size, and service populations along with their suggested construction schedule.

community plan See city plan and town plan.

community planning The process of planning a future community, or the guidance and shaping of the expansion of a current community, in an organized manner and with an organized layout, taking into account such considerations as convenience for its inhabitants, environmental conditions, social requirements, recreational facilities, aesthetic design, and economic feasibility. Such planning includes a study of present requirements and conditions as well as projections for the future, and often includes proposals for implementing the plan.

COMP 1. On drawings, abbr. for “compensate.” 2. On drawings, abbr. for “component.” 3. On drawings, abbr. for “composition.”

compacted volume 1. A measure of the volume of soil (or rocks) after its placement and compaction in a fill. 2. The volume of a solid, such as soil, after it has been subjected to compaction, 2.

compacted yards The compacted volume measured in cubic yards.

compacting factor The ratio of the weight of concrete which fills a container of standard size and shape (when allowed to fall into it under standard conditions of test) to the weight of fully compacted concrete which fills the same container.

compaction 1. The process of inducing a closer packing of the solid particles in freshly mixed concrete or mortar during placement by reducing the volume of voids, usually by vibration, centrifugation, tamping, or some combination of these actions. 2. A similar manipulation of other cementitious mixtures, soils, aggregate, or the like.

compaction pile One of a group of piles, driven in a pattern, to compact a surface layer of loose granular soil to increase its bearing capacity.

compactor 1. A machine that uses weight, vibration, or a combination of both, to achieve compaction. 2. A motor-driven machine (usually having one or more rams) which reduces the volume of waste material by subjecting it to pressure and forces it into a removable container.

compactor, 1

companion flange 1. A pipe flange which has been drilled so that it will fit the standard drilled holes in a flanged pipe or fitting. 2. A pipe flange that is suitable for connection with a flanged valve or fitting.

company town A community whose inhabitants depend predominantly on a single company for their employment and for many of their personal and family needs. The company may own and provide housing, schools, shopping facilities, recreational facilities, as well as church and library facilities for its workers and their families.

compartment A small space within a larger enclosed area, often separated by partitions.

compartmentalization The division of a building into fire-retardant sections, each of which can be closed off from the others, thereby impeding the spread of fire beyond its place of origin.

compartment ceiling A ceiling divided into panels, which are usually surrounded by moldings.

compartment wall British term for fire wall.

compass An instrument for drawing circles, measuring the distance between two points, etc.; consists of two pointed legs, movable on a joint or pivot, usually made so that one of the points can be detached for the insertion of a pen, extension, etc.

compass

compass brick An arch brick.

compass-headed arch A semicircular arch.

compass plane A plane having a curved baseplate (either concave or convex); for smoothing curved woodwork.

compass rafter A rafter which is curved on one or both sides.

compass roof 1. A roof having curved rafters or ties. 2. A form of timber roof in which the rafters, collar beams, and braces of each truss combine to form an arch.

compass saw A handsaw having a narrow blade; used to cut small intricate shapes or circles of small radius.

compass saw

compass survey A traverse survey which relies on the magnetic needle for orienting the sequence as a whole or for determining the bearings of the lines individually.

compass timber Timber that has been cut from a branch having a smooth curve of the required shape.

compass window 1. A rounded bay window that projects from the face of a wall; in plan, it forms the segment of a circle; same as bow window. 2. A semicircular oriel window. 3. A window having a rounded, usually semicircular, upper member.

compass work, circular work Joinery which has circular forms within its overall design.

compatible materials In building construction, those materials that can exist in close proximity without affecting each other detrimentally.

compensation 1. Payment for services rendered or products or materials furnished or delivered. 2. Payment in satisfaction of claims for damages suffered.

compensator In fire sprinkler systems, a device intended to minimize false alarms caused by small increases in service pressure of the water supply.

competitive bidding See open competitive selection.

COMPF On drawings, abbr. for “composition floor.”

completed operations insurance Liability insurance coverage for injuries to persons or damage to property occurring after an operation is completed but attributed to that operation; does not apply to damage to the completed work itself. An operation is completed (a) when all operations under the contract have been completed or abandoned; or (b) when all operations at one project site are completed; or (c) when the portion of the work out of which the injury or damage arises has been put to its intended use by the person or organization for whom that portion of the work was done.

complete fertilizer In landscape architecture, a fertilizer that contains all the nutrients that plants use in quantity, such as nitrogen, phosphorus, and potassium.

complete fusion In welding, fusion that has occurred over the entire base-metal surfaces exposed for welding and between all layers and passes.

completion bond, construction bond, contract bond The guarantee of a bonding company that a contractor will perform and deliver the work contracted for free of all encumbrances and liens.

completion date In the contract documents, the date of substantial completion of the work.

completion list See inspection list.

compliance See certificate of compliance.

compluvium The aperture in the center of the roof of the atrium in a Roman house, sloping inward to discharge rainwater into a cistern or tank.

compluvium, B

compo 1. Any composition material. 2. Mortar made with an appropriate proportion of cement, lime, and sand. 3. Various plastic cements and pastes which harden on exposure, as papiermâché.

component depreciation Depreciation of a building reckoned on the basis of the depreciation of individual elements of the building, thereby accounting for the building’s overall loss in utility with time.

composite A combination of conventional materials such as gypsum with reinforcement fibers such as carbon or glass so as to provide the material with greater strength.

composite arch An arch whose curves are struck from four centers, as in English Perpendicular Gothic; a mixed arch.

composite beam A structural beam composed of different materials so interconnected that the beam responds to loads as a unit.

composite board A type of hardboard, esp. one fabricated for use in heat insulation.

Composite capital The topmost member of a column of the Composite order; a Roman adaptation of a Corinthian capital, being much more elaborate; consists of volutes and convex molding between them, somewhat similar to the Ionic capital; has a circle of acanthus leaves applied to the lower part of the bell used in the Corinthian capital.

Composite capital

composite column A column in which a metal structural member is completely encased in concrete containing special and longitudinal reinforcement.

composite construction A type of construction made up of different materials (such as concrete and structural steel) or of members produced by different methods (such as cast-in-place concrete and precast concrete).

composite door A door made of a core material which is faced and edged with steel, wood, or a plastic-laminated material.

composite fire door A flush-design fire door; consists of a manufactured core material with chemically impregnated wood edge banding and untreated wood face veneers, or laminated plastic faces, or surrounded by and encased in steel.

composite girder 1. See plate girder. 2. A girder of composite construction.

composite joint A joint employing more than one means to hold the elements together, e.g., welding and bolting.

composite metal decking Sheets of corrugated-steel bonded securely with concrete fill to produce a reinforced steel deck. Also called a composite slab.

composite metal panel See sandwich panel.

Composite order In Classical architecture, one of the five Classical orders; combines characteristics of both the Corinthian and Ionic orders; similar to the Corinthian order, but much more embellished. The capital consists of volutes borrowed, with modifications, from the Ionic capital; the circle of acanthus leaves applied to the capital is borrowed from the Corinthian capital. See illustration under bases for an example of a base of the Composite order.

Composite order

composite pile 1. A pile comprised of different materials, e.g., concrete and wood. 2. A pile comprised of steel members which are fastened together, end-to-end, to form a single pile.

composite sample A sample of material which is obtained by blending two or more individual samples.

composite structure A structural element in which different types of materials share a load.

composite truss A truss whose compressive members are timber and whose tension members are metal (usually steel).

composite wall A wall built of a combination of two or more masonry units of different types of materials that are bonded together, one forming the facing of the wall and the other the backup.

composition board A building board which is fabricated of wood fibers, under pressure and at an elevated temperature, usually with a binder.

composition joint A bell-and-spigot joint that is sealed with a combination of materials such as cement and hemp, rope and rosin, etc.

composition mortar A plastic mixture of cement, lime, sand, and water.

composition nail (Brit.) A brass nail used in roofing, esp. to fix tiles and slates.

composition roofing See built-up roofing.

composition shingles See asphalt shingles.

compost A mixture usually consisting largely of decomposed organic material; used for fertilizing soil.

compound arch An arch formed by concentric arches set within one another.

compound beam, built-up beam A rectangular beam composed of smaller timbers over which planks are nailed on each side; the composite unit is joined together by bolting or by gluing.

compound beam

compound column Same as clustered column.

compound order Same as Composite order.

compound pier, compound pillar A pier composed of a conjunction of colonettes, generally attached to a central shaft; a clustered column. Also see bundle pier.

compound rafter One of a pair of two rafters, one spaced above the other; the one below is usually called the secondary rafter.

compound shake Wood shakes, 2 found in combination.

compound vault One whose construction appears to depend upon a pendant placed on each side, and within the walls that carry the main vault.

compound wall A wall which is constructed of more than one material; not of homogeneous construction.

COMPR 1. On drawings, abbr. for “composition roof.” 2. On drawings, abbr. for “compress.” 3. On drawings, abbr. for “compressor.”

compregnated wood, resin-treated wood Wood impregnated with a thermosetting resin, then subjected to heat and pressure to provide both resin curing and compression.

comprehensive general liability insurance A broad form of liability insurance covering claims for bodily injury and property damage which combines under one policy coverage for all liability exposures (except those specifically excluded) on a blanket basis and automatically covers new and unknown hazards that may develop; automatically includes contractual liability coverage for certain types of contracts.

comprehensive planning See community planning.

comprehensive services Professional services performed by the architect in addition to the basic services, in such related areas as project analysis, programming, land use studies, feasibility investigations, financing, construction management, and special consulting services.

compressed cork Same as corkboard.

compressed fiberboard See hardboard.

compressed straw slab See strawboard.

compressed wood, densified wood Wood which has been impregnated with resin and subjected to a high pressure to increase its density and strength.

compressibility The relative resistance (e.g., of a soil mass) to a change in volume upon being subjected to a compressive stress.

compression 1. The state of being compressed, or being shortened by a force. 2. The change in length produced in a test specimen by a compressive load.

compression bearing joint A joint, between two structural members in compression, that transmits the compressive stress from one member to the other.

compression coupling A coupling used to connect sections of hubless pipe (i.e., pipe without a hub), acid-resistant cast-iron pipe, or glass-pipe; consists of an inner elastomeric gasket and an outer metallic sleeve, with an integral bolt used to tighten and compress the seal.

compression failure 1. Mechanical failure in wood as a result of compression along the direction of the grain, due either to direct-end compression or to bending. 2. See primary compression failure.

compression coupling

compression faucet A faucet in which water flow is shut off by a flat disk that is screwed down onto its seat.

compression faucet

compression flange The widened portion of a beam or girder, such as the horizontal portion of the cross section of a simple-span T-beam, which is shortened by bending under a normal load.

compression gasket A gasket designed for use under compression.

compression glazing The setting of a pane of glass in an opening using a glazing gasket, 2 to hold the glass in place.

compression joint 1. Any joint formed by a fitting designed to join piping or tubing by means of pressure. 2. A joint having cup-shaped threaded nuts which, when tightened, compress tapered sleeves so they form a tight joint along the periphery of the tubing they connect.

compression loading A reduction in the thickness of an elastomeric element along the line of an externally applied force.

compression member Any member in which the primary stress is longitudinal compression.

compression molding A technique of thermoset molding; a molding compound is placed in a polished steel mold, and then heat and pressure are applied.

compression reinforcement Structural reinforcement which is designed to carry compressive stresses.

compression seal A material which provides a seal as a result of pressure between the faces of a joint.

compression set The permanent deformation of an elastomeric sealant, compressed so far that its internal structure is partially or completely destroyed and it no longer will assume its previous shape.

compression test On a specimen of mortar or concrete, a test to determine its compressive strength; in the US, unless otherwise specified, mortar test specimens are 2-in. cubes, and concrete test specimens are cylinders 6 in. in diameter and 12 in. high.

compression valve A valve in which water flow is shut off by a flat disk that is screwed down onto its seat.

compression wood Abnormal wood formed on the underside of branches and leaning trunks of softwoods; usually lower in strength; has unusual shrinkage characteristics.

compressive strain The strain caused by a compressive load.

compressive strength The maximum compressive stress which a material is capable of sustaining.

compressive stress 1. The stress which resists the shortening effect of an external compressive force. 2. For a test specimen: the compressive load per unit area of original cross section carried by the test specimen at any time during a compression test.

compressor A machine for compressing air or other gases which is a basic component in some refrigeration systems; draws vaporized refrigerant from the evaporator at a relatively low pressure, compresses it, and then discharges it to a condenser.

compressor-type liquid chiller Equipment utilizing a compressor, condensor, evaporator, controls, and accessories to cool water or other secondary liquid.

compulsory acquisition Same as eminent domain.

computer-aided design (CAD) The analysis and/or design, and/or modeling, and/or simulation, and/or layout of building design with the aid of a computer.

CONC 1. On drawings, abbr. for concrete. 2. On drawings, abbr. for “concentric.”

concameration 1. An arch or vault. 2. An apartment; a chamber.

concave joint A recessed masonry joint, formed in mortar by the use of a curved steel jointing tool; because of its curved shape it is very effective in resisting rain penetration; used in areas subjected to heavy rains and high winds.

concave joint

concealed Said of materials, components, controls, etc., that are rendered inaccessible by the finish or structure of a building.

concealed arch A camber arch having a slight convex rise so that when it is under a load, it has no sag.

concealed cleat A metal strap or cleat used to anchor sheet-metal roofing or flashing to the roof sheathing (or blocking); used to conceal the anchor under the sheet metal.

concealed cleat

concealed closer See overhead concealed closer.

concealed downspout A downspout (downpipe) that is covered or recessed, rather than surface-mounted.

concealed flashing On a roof, flashing which is entirely concealed by shingles.

concealed flashing

concealed-grid ceiling system A grid support system that is not visible from below; used in certain types of suspended acoustical tile ceilings.

concealed gutter A gutter built into the eaves of a roof, usually metal-lined.

concealed heating A system (such as a panel heating system) that employs heating elements which are concealed from view or are blended into the architectural features of a room.

concealed nailing 1. See blind nailing. 2. In roofing, see nailing.

concealed piping Piping which usually requires the removal of permanent construction to gain access to it.

concealed routing Routing at the bottom of a cabinet door or drawer to provide a means of opening and closing without pulls.

concealed suspension system A system for suspending an acoustical ceiling in which no suspension members are visible in the room.

concealed valley A type of valley on a roof; the shingles or slates are laid to the intersecting roof surfaces, covering the metal lining of the valley.

concentrated load A load acting on a very small area of a structure, as differentiated from a distributed load.

concentric Having a common center.

concentric castles Two fortified castles, one within the other, having concentric lines of defense; the inner curtain wall rises higher than the outer, thus providing lines of fire at an enemy at two different levels.

concentricity Conformance to a common center as, for example, the inner and outer walls of round tube.

concentric load See centric load.

concentric tendon One of a number of tendons which follow a line through the center of gravity of a prestressed concrete member.

concept plan A plan, 1 illustrating the assessment and possible suitable development of a site.

conch The domed roof of a semicircular apse.

concha 1. The semidome vaulting of an apse; also called a conch. 2. In Spanish architecture and its derivatives, a decorative element in the form of the interior of a sea scallop; see shell-headed.

concordant tendon In a statically indeterminate structure, a tendon that is coincident with the pressure line produced by the tendon.

concourse 1. An open space where several roads or paths meet. 2. An open space for accommodating large crowds in a building, as in a railway terminal.

concrete A composite stonelike material formed by mixing an aggregate (such as stones of irregular shape or crushed rock) with cement (which acts as the binding material) and water, then allowing the mixture to dry and harden; portland cement, now used in making concrete, was not developed until the 19th century. Also see average concrete, cyclopean concrete, poured concrete, reinforced concrete.

concrete admixture See admixture.

concrete aggregate See aggregate.

concrete agitation See concrete vibration.

concrete anchor See anchor.

concrete block A hollow or solid concrete masonry unit consisting of portland cement and suitable aggregates combined with water. Lime, fly ash, air-entraining agents, or other admixtures may be included. Sometimes incorrectly called cement block.

concrete bond, concrete bond plaster See bond plaster.

concrete block

concrete border 1. On a theater stage, the lighting batten nearest the proscenium. 2. A curtain concealing the lighting batten nearest the proscenium.

concrete boxing Pans, 5 of molded fiberglass or plywood, used to give the desired shape to poured concrete.

concrete breaker A compressed-air tool for breaking up concrete.

concrete brick A solid concrete masonry unit, rectangular in shape, usually not larger than 4 in. by 4 in. by 12 in. (10 cm by 10 cm by 30 cm); made from portland cement and suitable aggregates; may include other materials.

concrete cart See buggy.

concrete cancer Descriptive of condition of a spalling and/or fracturing of concrete as a result of the use of unsuitable ingredients in the concrete mix; eventually leads to corrosion.

concrete collar, doughnut A collar of reinforced concrete which is placed around an existing column so that it can be jacked up; the shrinkage of the concrete causes it to grip the column firmly.

concrete compliance conformity The agreement between the properties of concrete that were specified and those that were furnished by the supplier.

concrete column A column, 1 made of either reinforced or unreinforced concrete.

concrete curing blanket See curing blanket.

concrete curing compound A chemical compound which is applied to a concrete surface to prevent the loss of moisture during early stages of cement hydration.

concrete-encased beam A steel beam that is totally encased in concrete which is cast integrally with the concrete slab.

concrete-encased electrode See encased electrode.

concrete finishing machine 1. A machine mounted on flanged wheels which rides on forms or specially set tracks, used to finish concrete surfaces such as those of pavements. 2. A portable power-driven machine for floating and finishing concrete floors and slabs.

concrete flatwork Finishing operations on concrete floors and slabs.

concrete floor hardener A liquid or dry mixture of chemicals, minerals, metals, and/or other synthetic materials which produces a dense wear-resistant and/or nonslip and/or colored surface on concrete floors.

concrete footing See footing.

concrete form See form.

concrete form coating See form coating.

concrete formwork See formwork.

concrete frame construction A structure consisting of concrete beams, girders, and columns which are rigidly joined.

concrete grout Concrete that contains no coarse aggregate.

concrete gun A spray gun used in applying freshly mixed concrete; compressed air forces the concrete along a flexible hose and through a nozzle.

concrete hardener An admixture that significantly alters the rate of hydration of concrete so as to increase its strength.

concrete insert A plastic, wood fiber, or metal (often lead) plug, either built in a wall or ceiling or inserted by drilling; used as an anchor or support to hold attached loads.

concrete insert

concrete masonry 1. Construction consisting of concrete masonry units laid up in mortar or grout. 2. Poured concrete construction.

concrete masonry unit A block or brick cast of portland cement and suitable aggregate, with or without admixtures, and intended for laying up with other units as in normal stone masonry construction. Also see A-block, breeze block, cinder block, concrete block, concrete brick, etc.

concrete mixer, cement mixer A machine that mixes concrete ingredients by means of paddles or a rotating drum. Raw materials usually are introduced into the mixing drum through its open end and discharged by tilting the mixing drum to allow the concrete to pour out.

concrete nail A hardened-steel nail having a flat countersunk head and a diamond point; used for nailing to concrete or masonry.

concrete nail

concrete paint See cement paint.

concrete pile A concrete pile which is driven into the ground or otherwise placed; may be a precast pile, reinforced pile, or prestressed concrete pile.

concrete pipe A porous pipe, fabricated of concrete, used primarily for subsoil drainage.

concrete planer A self-propelled machine equipped with a series of rotating blades (or drums) for smoothing and leveling in refinishing old concrete pavement.

concrete plank A precast, prestressed, hollow-core concrete plank, usually relatively lightweight; used for floor and roof decking; may carry a structural topping.

concrete posttensioning See posttensioning.

concrete pump A machine that mixes concrete ingredients and then moves the concrete mixture through a hose to the point of placement. Also see pneumatic placement.

concrete reinforcement See reinforcement.

concrete retarder A material added to concrete to increase its setting time by decreasing the rate at which hydration takes place.

concrete saw A power-operated saw used in grooving uncured concrete (to prevent cracking) or in cutting hard concrete slabs.

concrete slab A flat, rectangular, reinforced concrete structural member; especially used for floors, roofs, pads, etc.

concrete vibrating machine A machine which compacts a layer of freshly mixed concrete by vibration.

concrete vibration Energetic agitation of freshly mixed concrete during placement by mechanical oscillation devices at moderately high frequency to assist in its consolidation.

concrete vibrator A device for agitating freshly mixed concrete during placement by mechanical oscillation at a moderately high frequency to assist in consolidation.

concreting paper A building paper.

concurrent loads Two or more elements of dead (or live) loads that, for purposes of design, are considered to act simultaneously.

condemnation 1. The process by which property of a private owner is taken for public use, without his consent, but upon the award and payment of just compensation, being in the nature of a forced sale. 2. A legal declaration that a piece of property or a building is unfit for use.

condensate The liquid formed by the condensation of a vapor; in steam heating, water is condensed from steam; in air conditioning, water is extracted from air.

condensate unit A packaged unit comprising a tank and pump which store and transfer condensed steam to a remote location.

condensation 1. In a refrigeration system, the process of changing the refrigerant into liquid by the extraction of heat. 2. See surface condensation.

condensation gutter, condensation channel, condensation groove, condensation trough A trough-like depression in the top of the interior sill of a glazed opening, to receive and carry off moisture forming on the indoor face of the glass.

condenser A heat-exchange device in a refrigeration system; consists of a vessel or arrangement of pipes or tubing in which refrigerant vapor is liquefied (condensed) by the removal of heat.

condenser tube Metal tubing manufactured to special requirements as to tolerances, finish, and temper; used in water cooling in a heat exchanger.

condensing unit In a refrigeration system, a single compact unit consisting of one or more power-driven compressors, condensers, liquid receivers (when required), and control accessories.

condition appraisal An estimate of the value of an asset based largely on an inspection of its current physical condition.

condition-based maintenance The condition monitoring of a building, used to predict failure of an item or element in the building and then take appropriate action to avoid such failure.

conditioned air Said of air within a building if it has been heated, cooled, humidified, and/or dehumidified.

condition monitoring The measurement of various parameters (such as vibration, bearing temperature, oil pressure, and performance) related to the mechanical condition of machinery; this information is used to predict whether a breakdown is apt occur in the very near future.

conditions of acceptance Criteria establishing the limits within which the measured or observed characteristics of a test specimen must fall in order for it to comply with stated requirements.

conditions of the bid Conditions set forth in the instructions to bidders, the notice to bidders or advertisement for bids, the invitation to bidders, or other similar documents prescribing the conditions under which bids are to be prepared, executed, submitted, received, and accepted.

conditions of the contract Those portions of the contract documents which define, set forth, or relate to: contract terminology; the rights and responsibilities of the contracting parties and of others involved in the work, 1; requirements for safety and for compliance with laws and regulations; general procedures for the orderly prosecution and management of the work; payments to the contractor; and similar provisions of a general, nontechnical nature.

conditory A repository for storing things, esp. an underground vault for the dead.

condominium A form of real estate ownership of a multifamily residential dwelling. Each occupant has 100% ownership of his own apartment and partial ownership of common elements such as hallways, elevators, plumbing, etc. Also see cooperative.

conductance See thermal conductance.

conduction See thermal conduction.

conductive flooring Flooring which has been designed to eliminate or prevent electrostatic buildup and electrostatic or mechanical sparking.

conductive loss The net decrease in heat within a space as a result of losses to the exterior and/or heat losses caused by exfiltration.

conductive rubber A rubber which has been mixed with carbon black in fabrication; has sufficient electrical conductivity to prevent electrostatic buildup.

conductivity See thermal conductivity, electrical conductivity.

conductor 1. A wire, cable, or device offering low resistance to the flow of electric current. 2. A material that transmits heat readily. 3. A downspout. 4. Any vertical pipe which conveys rainwater, including one within a building.

conductor head See leader head.

conductor shielding A metallic sheath which surrounds an electric conductor.

conduit 1. A tube or pipe used to protect electric wiring. 2. A tube or pipe used for conveying fluid. 3. Any channel intended for the conveyance of water, whether open or closed.

conduit body According to the NEC, a separate portion of an electrical conduit or tubing system that provides access through one or more removable covers to the interior of the system at a junction of two or more sections of the system or at a terminal point of the system.

conduit box See junction box.

conduit fitting 1. An accessory for a conduit, 1 system, such as a bushing or an access fitting. 2. In an electrical conduit system, an accessory such as an access fitting or bushing.

conduit hanger See hanger, 1.

cone bolt See cone-nut tie.

cone-cut veneer Wood veneer that has been cut in a manner similar to the sharpening of a pencil, to obtain circular sheets of highly figured veneer.

cone-drum cyclorama See rolling cyclorama.

conehead rivet A rivet which has a head shaped like a truncated cylindrical cone.

conehead rivet

cone-nut tie, cone bolt A type of tie rod used in a concrete form for a wall; has a cone at both ends; also acts as a spreader.

cone-nut tie

cone of depression A conically shaped depression in the soil around a point where an underground pump is located.

cone tile, cone hip tile See bonnet hip tile.

confession, confessio 1. The tomb of a martyr or confessor; if an altar was erected over the grave, the name was also extended to the altar and to the subterranean chamber in which it stood; in later times a basilica was sometimes erected over the chamber and the entire building was known as a confession. 2. The space immediately below, or in front of, the primary altar of a church.

confessional A small booth furnished with a seat for a priest and with a window, screen, or aperture so that the penitent, who is outside, may whisper in the priest’s ear without being seen.

confessional

configurated glass, figured glass Glass having an irregular surface in a pattern that has been rolled or formed during fabrication; used to obscure vision or to diffuse light.

configuration The spatial arrangement of wood particles, chips, flakes, or fibers used in particleboard, fiberboard, etc.

confined concrete A concrete which has closely-spaced special transverse reinforcement which restrains the concrete in directions perpendicular to the applied stress.

conflagration hazard The risk involved in the spread of fire by exterior exposure to and from adjoining structures or buildings.

confluent vent A vent serving more than one fixture vent or stack vent.

congé 1. See apophyge. 2. A quarter-round concave molding, tangent to a vertical surface and succeeded by a fillet parallel to that surface. 3. In ceramic tile work, a sanitary base or sanitary shoe.

congé, 1

congelated Same as frosted, 1.

conglomerate Rock consisting of rounded pebbles which are cemented together with a finer material.

congregate residence A building (or portion thereof) containing facilities for living, sanitation, and sleeping as required by the applicable building code; may include facilities for cooking and/or eating for occupancy other than by a family. This classification includes, for example, convents, dormitories, fraternity or sorority houses, and shelters.

conical roll See batten roll.

conical roof A roof in the shape of an inverted cone, usually atop a cylindrical tower; also called a candle-snuffer roof, or witch’s cap.

conical vault A vault having a cross section in the form of a circular arc, which is larger at one end than the other.

conical vault

conifer A cone-bearing tree or shrub of the gymnospermous order; a softwood which includes cypress, firs, pines, and spruce.

conisterium In ancient Greece and Rome, a room appended to a gymnasium or palaestra in which wrestlers were sprinkled with sand or dust after having been anointed with oil.

connected barn See continuous house.

connected load The electric load (in watts) on an electric system if all apparatus and equipment connected to the system are energized simultaneously.

Connecticut barn Same as Yankee barn.

connecting angle An angle section used to connect two structural members.

connecting block A plastic block containing metal wiring terminals; used to establish electrical connections.

connection In steel construction, a combination of joints capable of transmitting forces between two or more members.

connector 1. In an electric circuit, a device for joining two or more conductors, by a low-resistance path, without the use of a permanent splice. 2. A mechanical device for fastening together two or more pieces, members, or parts, including anchors, fasteners, or wall ties.

connector

connector plate In a truss, a prepunched toothed metal connector located at a joint or splice of a truss; designed to sustain the forces that occur at such a location.

consent of surety 1. Written consent of the surety on a performance bond and/or labor and material payment bond to such contract changes as change orders or reductions in the contractor’s retainage, or to final payment, or to waiving notification of contract changes. 2. Written consent of the surety, to an extension of time in a bid bond.

conservation The overseeing and maintenance of a building to prevent or arrest its decay or destruction, usually by applying a variety of measures. See building conservation and building preservation.

conservatory 1. A school for the teaching of music, drama, or other fine arts. 2. A structure chiefly used for growing flowers, plants, and out-of-season fruits and vegetables under protected conditions; it is attached to a dwelling, in contrast to a greenhouse which serves the same purpose but is usually a separate structure in a garden or field. Also see orangery, greenhouse, and hothouse.

consideration In a building contract, the compensation that shall be paid by one party to another party in return for products and/or services rendered.

consistency 1. The degree of firmness, or the relative ability of freshly mixed concrete, grout, or mortar to flow; usually measured by the slump test for concrete, and by the flow test for mortar, plaster, cement paste, or grout. Also see viscosity. 2. The property of a cohesive soil that describes its physical state.

consistency index Same as relative consistency.

consistency limits Same as Atterberg limits.

consistometer An apparatus for measuring the consistency of grouts, cement pastes, mortars, or concrete.

consistory A chamber used for a church court.

console 1. A decorative bracket in the form of a vertical scroll, projecting from a wall to support a cornice, a door or window head, a piece of sculpture, etc.; an ancon. 2. The cabinet from which an organ is played, including the keyboards, pedals, stops, etc. 3. A panel control desk or cabinet containing dials, meters, switches, and other apparatus for controlling mechanical, hydromechanical, or electrical equipment.

console, 1

console bracket A console, 1.

console lift A section of the floor area of a theater or auditorium that can be raised or lowered.

console table A table attached to a wall and supported on consoles.

consolidation 1. The compaction of freshly placed concrete or mortar, usually by vibration, centrifugation, or tamping, to mold it within forms and around embedded parts and reinforcement and to eliminate voids other than entrained air. Also see compaction. 2. The process whereby soil particles are packed more closely by the application of continued pressure.

consolidation grouting 1. The injection of fluid grouting, usually portland cement and sand, into a compressible soil mass to displace it and form a structure for support. 2. Same as area grouting.

consolidation settlement Of loaded clay, a settlement which takes place over a period of years.

con spec Abbr. for “construction specification.”

CONST On drawings, abbr. for construction.

constant-voltage transformer A special transformer which is designed to provide constant voltage at its output, independent of voltage variations in the line to which its input is connected.

constant volume system An air-conditioning system which supplies air at a fixed volume per unit time; the temperature of the supplied air is used to regulate the temperature of the air-conditioned space if there are variations in the load on the system.

constant-wattage ballast A ballast used with a high-intensity discharge lamp to minimize the effects of voltage variations and to provide a high power-factor.

constratum In ancient Rome, a flooring constructed of planks.

construction 1. All the on-site work done in building or altering structures, from land clearance through completion, including excavation, erection, and the assembly and installation of components and equipment. 2. A structure. 3. The manner in which something is built.

construction administrator An individual who oversees the responsibilities of a contract for construction. These responsibilities include reviewing and certifying the amount due to the contractor, preparing change orders, and conducting site inspections to determine dates of substantial completion and final completion. Compare with construction manager.

construction bolt Any one of a number of common steel bolts, used during construction as a temporary fastening device, such as a bolt to hold forms together.

construction bond A completion bond.

construction budget 1. The sum established by the owner as available for construction of the project. 2. The stipulated highest acceptable bid price or, in the case of a project involving multiple construction contracts, the stipulated aggregate total of the highest acceptable bid prices.

construction class A classification based on the fire-resistance ratings of the construction of a building or its parts.

construction close-out log A record of final submissions on a construction job, including warranties, operations, and maintenance. Usually compiled and completed near the end of construction.

construction contract See contract for construction.

construction contract administrator See construction administrator.

construction cost The cost of all the construction portions of a project, generally based upon the sum of the construction contract(s) and other direct construction costs; does not include the compensation paid to the architect and consultants, the cost of the land, right-of-way, or other costs which are defined in the contract documents as being the responsibility of the owner.

construction documents The working drawings and specifications.

construction documents phase The third phase of the architect’s basic services. In this phase the architect prepares from the approved design development documents, for approval by the owner, the working drawings and specifications and the necessary bidding information. In this phase the architect also assists the owner in the preparation of bidding forms, the conditions of the contract, and the form of agreement between the owner and the contractor.

construction drawings The portion of the contract documents that are graphic representations of the work to be done in the construction of a building.

construction equipment All machinery, derricks, hoists, ladders, materials-handling equipment, platforms, runways, safeguards and protective devices, and scaffolds, as well as other equipment, used in construction operations.

construction inspector See project representative.

construction joint 1. A joint where two successive placements of concrete meet. 2. A separation provided in a building which allows its component parts to move with respect to each other. The cause of such movement may be thermal, seismic, or wind loading.

construction loads The loads, 1 during construction, to which a structure is subjected.

construction loan A loan to a builder for a short term, financing construction prior to permanent financing.

construction management The special management services performed by the architect or others during the construction phase of the project, under separate or special agreement with the owner. This is not part of the architect’s basic services, but is an additional service sometimes included in comprehensive services.

construction manager 1. A person who is appointed by the owner to work as the owner’s agent in the construction work, preparing bidding documents and contract documents, arranging construction contracts, and managing the contractors so that all work on the project is completed on time and within budget, in accordance with contractual agreements. 2. The person who has been designated by the owner to provide special management services during the construction phase of a building project.

construction phase—administration of the construction contract The fifth and final phase of the architect’s basic services, which includes the architect’s general administration of the construction contract(s). Also see contract administration.

Construction Specifications Canada (CSC) A nonprofit organization devoted to the standardization of construction documents in Canada; used in both the private and public sectors. The MasterFormat has been adopted as the basis for a numbering and titling system for the Canadian National Master Specification (NMS). Head office: 120 Carlton St., Toronto ON M5A 4K2, Canada.

Construction Specifications Institute (CSI) A non-profit technical organization serving construction specifiers and related building professionals in the US. CSI publishes MasterFormat jointly with the Construction Specifications Canada. Head office: 99 Canal Center Plaza, Alexandria, VA 22314.

construction survey See engineering survey.

construction wrench A wrench having an open end for turning nuts and bolts; the other end tapers to a blunt point which is used to align mating holes in steel construction.

constructive eviction The rendering of leased premises uninhabitable because of the landlord’s improper acts of commission or omission; gives rise to the same legal consequences as an unlawful eviction. See eviction.

Constructivism A movement which originated in Moscow after 1917, primarily in sculpture, but with broad applications to architecture. The expression of construction was to be the basis for all building design, with emphasis on functional machine parts. Tatlin’s project of a monument to the Third International in Moscow (1920) is the most famous example.

Constructivism: Tatlin’s project

constructor One who is in the business of constructing elements of the built environment, acting under the terms of a construction contract.

consulate A building or place where a consul conducts official business.

consulting engineer An engineer, usually employed by the owner or architect to perform specific tasks of engineering design for a portion of the construction contract.

consultant An individual or organization engaged by the owner or the architect to render professional consulting services complementing or supplementing the architect’s services.

CONT On drawings, abbr. for “continue.”

contact A part which is an electric conductor and which provides a low-resistance path for current flow upon mating with another conducting part with which it is designed to operate.

contact adhesive, contact-bond adhesive, dry-bond adhesive An adhesive that is apparently dry to the touch and adheres instantaneously upon contact.

contact-bond adhesive See contact adhesive.

contact ceiling A ceiling that is secured directly to the construction above, without the use of furring channels.

contactor Any device for repeatedly opening and closing an electric power circuit.

contact pressure Pressure, produced by the weight of a footing and all the forces acting on it, which acts at and perpendicular to the contact area between the footing and the soil.

contact pressure adhesive An adhesive that is permanently tacky at room temperature and adheres to many types of surfaces upon contact, requiring little pressure in application.

contact splice A type of connection between reinforcing bars in reinforced concrete; the bars are lapped and are in direct contact.

container packer A refuse compactor that compresses refuse within a steel container. The container is latched to the compactor by special locking devices.

containerized plant In landscape architecture, a growing plant, together with its root system, that is sold intact in a container.

containment grouting Same as perimeter grouting.

contamination The introduction of sewage, wastes, and/or chemicals (or other material) into a potable water supply that render it unfit for its intended purpose.

Contemporary style An imprecise term applied to any of a number of architectural modes popular from about the 1940s through the 1970s and beyond, sometimes included under the term modern architecture; often characterized by widely overhanging eaves, exposed roof beams, and front-facing gables with heavy piers that support the gables; often, a balcony with an overhanging sunscreen, roof decks, and a patio that may serve as an extension of the living area; another type has a façade and flat roof resembling that of the International style.

contents hazard classification The classification of the potential danger of building contents as ordinary, high, or low.

contextualism The “fitting-in” of a building with surrounding buildings so that it is in harmony with them, especially in terms of scale, form, mass, and color.

contignation A framework, as of beams.

continental cabin A one-and-one-half-story log house attributed to German-speaking immigrants to colonial America; usually consisted of a large room at the front of the house, a bedroom behind it, and a long narrow kitchen along one side. A sizable stove in the kitchen was used both for cooking and for heating the adjacent large room.

continental seating A seating arrangement in an auditorium in which the rows of seats are unbroken by aisles or crossovers; access to the rows is from an aisle at the end of the rows or from doors along the sidewalls.

contingency An amount of money, included in the budget for building construction, that is uncommitted for any specific purpose. This amount is intended to cover the cost of unforeseen factors related to the construction which are not specifically addressed in the budget.

contingency allowance A sum designated to cover unpredictable or unforeseen items of work, 1 or changes subsequently required by the owner.

contingent agreement Any agreement under which the rights or obligations of a party are subject to the happening of a stated contingency, e.g., an agreement between an owner and an architect in which part or all of the architect’s compensation is contingent upon the owner’s obtaining funds for the project (such as by successful referendum, sale of bonds, or other financing), or upon some other specially prescribed condition.

continuous accessible path of travel See accessible route.

continuous acoustical ceiling A suspended acoustical ceiling in which the top of a partition extends only to the lower surface of the ceiling.

continuous beam A beam which extends over three or more supports, joined together so that, for a given load on one span, the effect on the other spans can be calculated.

continuous block core, edge-glued core, stave core A solid core consisting of blocks of wood which are bonded together and sanded to a smooth uniform thickness; used in wood doors, panels, etc.

continuous footing A combined footing, of prismatic or truncated shape, which supports two or more columns in a row.

continuous foundation A foundation which supports a number of independent loads.

continuous girder A girder with more than two supports.

continuous grading A particle-size distribution for material such as an aggregate in which all intermediate-size fractions are present, as opposed to gap grading.

continuous handrail Handrail for a geometrical stair.

continuous header A top plate consisting of timbers on end which are joined (along their lengths and at corners) to form a continuous, rigid framework around a structure, sufficiently strong to act as a lintel over wall openings.

continuous header

continuous hinge, piano hinge A hinge having the same length as the moving part to which it is applied.

continuous house A house that is connected to several other ancillary facilities such as a barn, privy, shed, and/or stable; advantageous in areas having a harsh winter climate because this arrangement permits the residents to use these dependencies without going outdoors. Compare with telescope house.

continuous hinge

continuous impost In Gothic architecture, the moldings of an arch when carried down to the floor without interruption or anything to mark the impost point.

continuous impost

continuous kiln See progressive kiln.

continuous load Said of an electrical load in which the maximum current is expected to continue for at least 3 hours at a time.

continuously reinforced pavement A pavement having no transverse joints, except tied construction joints which are placed between successive days’ concreting, with sufficient longitudinal reinforcement, adequately lapped to develop tensile continuity.

continuous mixer A mixer for concrete or mortar into which ingredients are fed without stopping and from which the mix is discharged in a continuous stream, in contrast to the periodic discharge of a batch mixer.

continuous moving formwork See slip form.

continuous-pressure electric elevator An electric elevator operated by means of push buttons in the elevator car and at landings, requiring that a button be held manually to keep the car in motion.

continuous ridge vent A screened, water-shielded opening for a ventilator that runs continuously along the ridge of a gable roof.

continuous rating The maximum constant load that can be carried by a piece of electric equipment without exceeding a designated temperature rise.

continuous slab A slab which extends as a unit over three or more supports in a given direction.

continuous span A span which is formed of a series of consecutive spans (over three or more supports) that are continuously or rigidly connected so that bending moment may be transmitted from one span to the adjacent ones.

continuous string A string for a geometrical stair.

continuous truss A truss that extends over three or more supports.

continuous vent A vertical vent that is a continuation of a drain, a soil pipe, or a waste pipe to which the vent connects.

continuous vent

continuous waste A drain from two or more plumbing fixtures connected to a single trap.

continuous waste

continuous waste-and-vent A waste pipe and a vent pipe which are in a straight line, the latter being a continuation of the former.

contour basin A level basin on a sloping site to catch rainfall.

contour curtain A theater stage curtain which can be raised in separate folds by individual lines which are attached to its component sections, thereby controlling its shape or contour.

contour interval The vertical distance between adjacent contour lines.

contour line A line on a map or drawing representing points of equal elevation on the ground.

contour lines

contour map A topographic map which portrays relief by the use of contour lines which connect points of equal elevation; the closer the spacing of the lines, the greater the relative slope.

CONTR On drawings, abbr. for contractor.

contract A legally enforceable promise or agreement between two or among several persons. Also see agreement.

contract administration The duties and responsibilities of the architect during the construction phase.

contract award The notification by an owner to a bidder that his offer, or a negotiated proposal, has been accepted. This award establishes a legal obligation between the parties.

contract bond See completion bond.

contract carpet A carpet, often heavy-duty, that is purchased in bulk for non-domestic use.

contract date Same as date of agreement.

contract documents Those documents that comprise a contract, e.g., in a construction contract, the owner-contractor agreement, conditions of the contract (general, supplementary, and other conditions), plans and/or drawings, specifications, all addenda, modifications, and changes thereto, together with any other items stipulated as being specifically included.

contract documents

contract drawings The drawings that form a part of the contract documents.

contract for construction An agreement between the owner and contractor in which the contractor agrees to construct the owner’s building (or other described project) in accordance with the contract documents and within a specified time, for a mutually-agreed upon consideration to be paid by the owner.

contracting officer The person designated as an official representative of the owner with specific authority to act in his behalf in connection with a project.

contraction Of concrete, the sum of volume changes occurring as the result of all processes affecting the bulk volume of a mass of concrete.

contraction joint 1. An expansion joint, 1. 2. A joint between adjacent parts of a structure which permits movement between them resulting from contraction.

contraction joint grouting The injection of grout into a contraction joint.

contract limit A limit line or perimeter line established on the drawings or elsewhere in the contract documents defining the boundaries of the site available to the contractor for construction purposes.

contract load The load specified in the contract for the purchase of an elevator, or the load specified in the application for the building permit.

contract manager See contracting officer and construction manager.

contract modification Additions to, deletions from, or modifications of the work, 1 to be done, after the construction agreement has been signed.

contractor One who undertakes responsibility for the performance of construction work, including the provision of labor and materials, in accordance with plans and specifications and under a contract specifying cost and schedule for completion of the work; the person or organization responsible for performing the work, 1 and identified as such in the owner-contractor agreement.

contractor’s affidavit A certified statement of the contractor, properly notarized, relating to payment of debts and claims, release of liens, or similar matters requiring specific evidence for the protection of the owner. Also see noncollusion affidavit.

contractor’s breakdown See schedule of values.

contractor’s estimate 1. A forecast of construction cost, as opposed to a firm proposal, prepared by a contractor for a project or a portion thereof. 2. A term sometimes used to denote a contractor’s application or request for a progress payment. Also see application for payment.

contractor’s liability insurance Insurance purchased and maintained by the contractor to protect him from specified claims which may arise out of or result from his operations under the contract, whether such operations be by himself or by any subcontractor or by anyone directly or indirectly employed by any of them, or by anyone for whose acts any of them may be liable.

contractor’s option A provision of the contract documents under which the contractor may select certain specified materials, methods, or systems at his own option, without change in the contract sum.

contractor’s proposal See bid.

contractor’s qualification statement A statement of the contractor’s qualifications, experience, financial condition, business history, and staff composition. This statement, together with listed business and professional references, is intended to provide evidence of the contractor’s ability to perform the work, 1 and to assume the responsibilities required by the contract documents.

contract period See contract time.

contract speed The speed specified in the contract for the purchase of an elevator, or the speed specified in the application for the building permit.

contract sum The price stated in the owner-contractor agreement, which is the total amount payable by the owner to the contractor for the performance of the work, 1 under the contract documents; can be adjusted only by a change order.

contract time The period of time stipulated in the construction contract for the substantial completion of the work.

contractual liability Liability assumed by a party under a contract by express language, implication, or operation of law; includes not only the obligation of a party to perform in accordance with the contract but also such other obligations as may be assumed, e.g., those arising from indemnification or “hold harmless” clauses.

contractura The tapering of a column from bottom to top.

contraflexure point Same as point of inflection.

contramure Same as countermure.

contrasted arch An arch, such as an ogee arch, containing a reverse curve.

contrast ratio The ratio of the reflectance of a dry paint film over a black substrate having 5 percent reflectance or less, to the reflectance of the same paint equivalently applied over a substrate having an 80 percent reflectance.

contrast sensitivity The ability to detect the presence of differences in luminance; the reciprocal of the contrast threshold.

contrast threshold 1. The minimum perceptible contrast for a given state of adaptation of the eye. 2. The luminance contrast which can barely be detected by an observer.

contravallation In military architecture, a series of redoubts and breastworks to guard against sorties of an enemy garrison.

contrefort In Medieval architecture, a brickwork revetment for ramparts on the side of a terreplein, or for counterscarps and gorges.

contre-imbrication An ornamental pattern on a surface that forms overlapping elements which are below the general plane of the surface. This is in contrast to imbrication, in which the overlapping elements are above the general plane of the surface.

contrevents In French Vernacular architecture, same as wood shutters.

contributing chapel In Spanish Colonial architecture, a chapel usually having no permanent padre to officiate at religious ceremonies, relying instead on the part-time assistance of visiting priests.

control Any device for regulating a system or component during its normal (manual or automatic) operation; it is responsive, during automatic operation, to the property (such as pressure or temperature) whose magnitude is to be regulated.

control area A building (or portion thereof) in which exempted quantities of hazardous materials may be dispensed, handled, stored, or used.

control board, control desk, control panel control rack One or more panels comprised of an assembly of master switches, adjustable controls, indicating dials or numerical readouts, and the like, used to control and monitor the state of a remotely operated system (e.g., a lighting system, sound system, or air conditioning system) and equipment.

control desk A position in a library, public lobby, hospital, etc., where activities may be overseen or supervised.

control factor The ratio of the minimum compressive strength of a material, such as concrete, to the average compressive strength.

control gap Same as control joint.

control joint A groove which is formed, sawed, or tooled in a concrete or masonry structure to regulate the location and amount of cracking and separation resulting from the dimensional change of different parts of the structure, thereby avoiding the development of high stresses.

control joint

control-joint grouting The injection of grout into a control joint.

controlled construction The construction of a building or structure, or of a part thereof, by an architect and/or licensed professional engineer in accordance with code requirements and accepted engineering practice.

controlled fill Fill (intended as a bearing for a structural load) which is placed in layers, compacted, and tested to ensure that it meets specified compaction standards as determined by laboratory tests on a series of soil samples from the fill material.

controlled flow Said of a roof drainage system that regulates the drainage of rainwater so that it is essentially uniform.

controlled-flow roof drainage system A roof drainage system that permits rainwater to drain off a roof much more slowly than the rate at which it accumulates; after the storm has abated, the accumulation drains off at a controlled rate.

controlled low-strength material A material resulting in a compressive strength of no more than 1200 pounds per square inch (8300 kPa).

controlled materials Materials that are certified by an appropriately accredited agency as having met the accepted engineering standards for good quality.

controller An electric device (or combination of devices) designed to initiate one or more functions of operation, such as starting, stopping, reversing, and speed changing, of the apparatus to which it is connected; operation may be manual or automatic.

control room, console room A small room, in or adjacent to an auditorium, having a view of the stage, in which the lighting or sound-control consoles are located.

control set-point In an automatic control system, the point at which the value a control setting must be pre-set in order to achieve a desired value. For example, in an air-conditioning system, the set-point is the value of temperature that must be pre-set in order to establish the desired temperature in the conditioned space.

control survey A survey, 1 that provides horizontal and vertical positions of points to which supplementary surveys are adjusted.

control valve Any valve used to regulate fluid flow.

CONT W On drawings, abbr. for “continuous window.”

conv. Abbr. for convector.

convalescent home A medical-care institution providing services for patients recovering from acute or postoperative conditions who do not require the level of skilled services provided by an extended-care facility or warrant custodial care such as that normally rendered in nursing homes.

convection Heat transmission, either natural or forced (by means of a fan), by currents of air resulting from differences in density due to temperature differences in the heated space.

convection circulation In a hot-water heating system, the movement of water through the pipes as a result of gravity which causes the lighter, warm water in the system to rise, and the cool water to fall.

convection current The transfer of heat that results from the movement of air from one location to another, usually as a result of a stream of air produced by thermal convection caused by differences in temperature.

convection heating Heating which results from the movement of air (or any other gas or liquid), carrying heat from the hotter to the cooler spaces.

convection loss Heat loss in a building resulting from temperature differences in the heated space.

convective movement See natural convection.

convector A surface designed to transfer its heat to a surrounding fluid largely or wholly by convection; units for water or steam heating usually are installed against the wall or in a recess in the wall.

convector

convenience outlet A receptacle outlet which is mounted on the wall of a room to supply electricity for lamps, appliances, etc.

convenience receptacle Same as receptacle.

convent 1. A religious community: friars, monks, or nuns (now usually nuns). 2. A group of buildings occupied by such a community.

conventional design Design procedures using stresses or moments which have been determined by widely accepted methods.

conventional door Any door (including a kalamein door) except one of a special type, such as a fire door, a sound-attenuating door, or the like.

conventional sprinkler In a fire protection system, a sprinkler providing a spherical water distribution directed towards the floor and ceiling; directs 40 to 60 percent of the total water flow initially in a downward direction.

convention center An air-conditioned multipurpose facility generally used for meetings, conventions, and the display of merchandise by a wide variety of industrial groups, professional groups, and trade organizations. The size of the facility ranges from small to very large—sometimes over more than 2 million square feet (approximately 18 hectares). The interior must be flexible so that it can be divided into various-sized spaces. Regardless of size, a convention center requires meeting spaces, movable partitions to subdivide these spaces, sanitary facilities, loading docks, adequate heating, cooling, electrical and communications equipment, and trained maintenance staff.

convento In Spanish architecture and its derivatives, a convent or monastery usually containing living quarters, workrooms, storerooms, a balcony, and patio.

conversion 1. See breaking down. 2. A change in the use of a building to another use which has different requirements according to code (e.g., different exit, fire-resistance, light and ventilation, loading, structural, or zoning requirements).

conversion burner A burner, together with its control unit, which is designed as a replacement for an existing boiler or furnace.

conversion factor A quantity by which the numerical value in one system of units must be multiplied to arrive at the numerical value in another system of units.

converted timber Timber sawn into lumber or boards.

converter A device or machine used to change alternating-current power to direct-current power or vice versa.

conveyance 1. The transfer of property from one person to another. 2. The document or instrument by which this transfer is effected.

conveying hose Same as delivery hose.

conveyor A motor-driven mechanism used for the continuous transport of material, e.g., an endless belt or series of rollers.

cooked glue Glue requiring heating before use.

cook house Same as outkitchen.

coolant See cooling medium.

cool cellar A cellar, 1 beneath a house, whose temperature is low enough to store beverages, dairy products, meat, and/or vegetables.

cooler 1. A thermally insulated enclosure, kept at a reduced temperature by means of refrigeration. 2. An air conditioner.

coolhouse A greenhouse which is maintained at a cool temperature above freezing.

cooling capacity A measure of the amount of heat that can be removed from a building (or section thereof) in one hour.

cooling load The amount of heat that must be removed from a building to maintain a comfortable temperature for its occupants.

cooling medium, coolant A fluid which conducts heat from one or more heat sources and transports it to a heat exchanger, where the heat is removed and disposed of.

cooling pond See roof pond.

cooling range In a water-cooling device, the difference between the average temperature of the water entering the device and the average temperature of the water leaving it.

cooling tower A structure, usually on the roof of a building, over which water is circulated, so as to cool it evaporatively by contact with air.

cooling tower of the induced-draft, propeller type

cooperative A form of real estate ownership of a multi-unit housing structure by a non-profit corporation which leases portions of the property to its stockholders. The stockholders are part owners of the corporation; they do not own their own apartments. Periodic payments, usually monthly, by stockholders are used to meet costs of ownership, such as mortgage payments, property maintenance, taxes, and repairs. Such shareholding by the tenant allows him to occupy a dwelling unit while not possessing direct title to it.

cooperculum The cover of a baldachin or ciborium.

coopered joint In a curved surface, a joint similar in appearance to a joint in a barrel.

COORD On drawings, abbr. for “coordinate.”

coordinator A device used on a pair of exit doors to ensure that the inactive leaf is permitted to close before the active leaf; required on a door having an overlapping astragal.

cop Same as merlon.

cop. Abbr. for coping.

copal Resin of natural origin used in varnishes to provide gloss and hardness.

copal varnish A high-gloss varnish made with a drying oil, such as linseed oil, and copal.

cope 1. To cut or shape the end of a molded wood member so that it will cover and fit the contour of an adjoining member. 2. To notch a steel beam, channel, etc., so that another member may be fitted against it. 3. A coping. 4. To form a coping.

cope chisel Same as cape chisel.

coped joint, scribed joint A joint between two moldings; one molding is cut to the profile of the second.

coped joint

copestone Same as coping stone.

coping A protective cap, top, or cover of wall, parapet, pilaster, or chimney; often of stone, terra-cotta, concrete, metal, or wood. May be flat, but commonly sloping, double-beveled, or curved to shed water so as to protect masonry below from penetration of water from above. Most effective if extended beyond wall face and cut with a drip. Also see featheredge coping.

coping of terra-cotta

coping block A concrete masonry unit having a solid top, for use as a coping at the top and finishing course in wall construction.

coping brick A brick which is specially manufactured for use as the top course in a coping; caps the top of an exposed wall.

coping course A horizontal layer of masonry units that forms a coping.

coping saw A light narrow-bladed saw with fine teeth, held in a U-shaped tension frame; used for cutting small curves in wood.

coping saw used in cutting

coping stone, capstone, copestone A stone which forms a coping.

coping stone

copper A lustrous reddish metal, highly ductile and malleable; has high tensile strength, is an excellent electrical and thermal conductor, is available in a wide variety of shapes; widely used for downspouts, electrical conductors, flashing, gutters, roofing, etc.

copper alloy Metal having a specified copper content of less than 99.3% but more than 40% and having no other element in excess of the copper content (except in the case of certain copper-nickel-zinc alloys, in which zinc slightly exceeds the copper content).

copper bit, coppering bit A gas-heated soldering iron used by plumbers.

copper fitting A fitting (fabricated of wrought copper, cast brass, or bronze) which may be joined to copper or brass pipe by solder, screw threads, or a compression fit.

copper fitting

copper glazing Same as copperlight glazing.

copperlight glazing, copper glazing, electrocopper glazing, fire-retarding glazing A fire-retardant glazing consisting of a number of individual panes of glass which are separated by strips of electrically welded copper.

copperplating Depositing a protective layer of copper on the surface of another metal, either by the electrolytic method or by dipping.

copper roofing A flexible metal roof covering made of copper sheets, joined by seams. As the copper oxidizes, it develops a green coating on its surface called a patina.

copper sheet Copper roofing material used to cover flat, domed, or sloping roofs; usually weighs from ½ to 2 lb per sq ft (2.5 to 10 kg per sq m).

copper slate See lead slate.

coppersmith’s hammer A hammer having a long, curved, ball-shaped peen; used to beat copper sheeting into the desired shape.

copper tube A seamless tube made from almost pure copper (99.9 percent); available only in drawn or soft form, with plain ends. Joints for this pipe can either be soldered or brazed. Also see type-DWV tubing.

coquillage A representation of the forms of seashells and the like, as a decorative carving.

coquina A soft limestone formed primarily of broken shells and coral; cut into blocks and used in construction.

cora A draped female figure used in architecture; a caryatid.

COR BD On drawings, abbr. for corner bead.

corbeil, corbeille An ornament resembling a basket, esp. a finial. Also see calathus.

corbel 1. In masonry, a projection or one of a series of projections, each stepped progressively outward with increasing height, and usually projecting from a wall or chimney; serves as a support for an overhanging member or course, 1 above, or as a purely decorative element. 2. A projecting stone that supports a superincumbent weight. 3. A heavy bracket, often decorated, that is set into an adobe wall to act as a bearing surface to support a roof beam.

brick wall having a corbel, 1

corbel, 2

corbel arch Masonry built over a wall opening by uniformly advancing courses from each side until they meet at a midpoint. The stepped reveals may be smoothed, even arcuated, but no arch action is effected—not a true arch.

corbel arch

corbel course A masonry course acting as a corbel, or an ornament of similar appearance. Also see stringcourse.

corbeled chimney cap The crowning termination of a chimney in which successive courses of bricks step outward with increasing height.

corbeled cornice See corbie step.

corbel gable Erroneous for corbie gable.

corbeling Same as corbel, 1.

corbeling iron, corbel pin A metal pin used (instead of corbeled brickwork) for carrying a wall plate.

corbel out To build out one or more courses of brick or stone from the face of a wall, forming a support for timbers.

corbel piece See bolster.

corbel pin See corbeling iron.

corbel ring Same as annulet.

corbel-step Erroneous for corbiestep.

corbel table A projecting stringcourse or masonry strip supported by corbels. Also see arched corbel table.

corbel table

corbel vault, corbeled vault A masonry roof constructed from opposite walls, or from a circular base, by shifting courses slightly and regularly inward until they meet. The resulting stepped surface can be smoothed or curved, but no arch action is incurred.

corbie gable, crow gable, step gable A gable having a stepped edge.

corbiestep, catstep, crowstep The stepped edge of a gable masking a pitched roof, found in northern European masonry, 14th to 17th cent., and in derivatives.

corbiestep

Corbusian style In the style of Le Corbusier (1887–1965), the celebrated proponent of Modern architecture in France.

cord See electric cord.

corded door An accordion door fabricated of narrow wood slats which are interconnected with cotton cord or fabric tapes; usually suspended from ceiling-mounted tracks.

cordon 1. A stringcourse or belt course. 2. A semi-circular masonry projection, placed at the top of a wall, to discharge water to each side.

corduroy work A surface finish consisting of a series of narrow, adjacent, parallel convex reeds; the reverse of fluting.

core 1. The center of a plywood or crossbanded construction; it may consist of lumber (solid or glued) or particleboard; serves as a base for veneer. 2. The internal structure in a hollow-core door. 3. The wood chips cut from a mortise. 4. The metal bar to which a handrail is attached. 5. The internal structure which serves as a base for complex plasterwork. 6. The molded open space in a concrete masonry unit. 7. The filling within a thick hollow stone wall. 8. The filling between a lintel and relieving arches. 9. A cylindrical sample of hardened concrete or rock obtained by means of a core barrel and drill. 10. A part of a multistory building, containing a variety of service and utility functions, as elevators, stairwells, etc. 11. That part of a magnetic circuit (usually steel or iron laminations) about which are wound coils in electromagnetic devices such as transformers, solenoids, relays, etc.; a magnetic core. 12. (Brit.) The conductor of a cable with its insulation, but not including any outer protective covering. 13. That portion of a grille, 2 contained within the frame. 14. Of gypsum board, the hardened material filling the space between a face paper and a back paper; consists primarily of gypsum with additives. 15. (British) Same as blockout.

core, 6

core area Of a grille for an air diffuser, the total area within the outer edges of the outer opening through which air can pass.

core barrel The hollow cutting tool of a core drill; consists of a section of pipe which has a carbide insert or diamond cutting edge.

coreboard, Brit. battenboard A wood-base panel used in plywood or laminated core constructions; the core, 1, to which faces are glued.

core boring In the ground at a construction site, a core obtained with a rotating tool; used to determine the nature and/or thickness of the underlying rock.

cored beam 1. A beam having a partially hollow cross section. 2. A beam from which core samples have been taken.

cored block, cored tile A cast gypsum building unit.

core bracing The vertical elements of a lateral support system around the core, 10 of a building having permanent interior walls.

cored cellular material Cellular material containing a multiplicity of holes which are molded or cut into the material in some pattern, usually perpendicular to the largest surface, and extending part or all the way through the piece.

core drill A drill used to remove a sample of rock in situ, for determining bedrock profiles or for obtaining a core for testing; the sample is retained in the core barrel.

core driver A hardwood or steel cylinder which is the same size as a hole through which it is driven; used to clear the hole of chips.

cored masonry unit See hollow masonry unit.

core frame See buck frame.

core hole In a structural clay tile, same as cell, 1.

core module A module, 1 containing electrical, heating, plumbing, and related subsystems.

core rail A steel rail, 1 that connects the tops of balusters supporting a stair handrail.

core sample Same as core, 9.

core test A compression test on a concrete sample cut from hardened concrete by means of a core drill.

coring Removing a core from a concrete structure or rock foundation, for test purposes.

coring out The process of removing droppings after a parge coat has been applied to the inside of a chimney shaft.

Corinthian capital The uppermost member of a column of the Corinthian order.

Corinthian order In Classical architecture, the slenderest and most ornate of the three original Greek orders; commonly has an elaborate cornice and a fluted shaft. For an illustration of a Corinthian base, see bases.

cork The outer bark of the cork oak tree; lightweight, used as thermal insulation, for gaskets, and in vibration control.

Corinthian capital

Corinthian order

corkboard Cork granules molded to shape, compressed, and baked in a rectangular block or board shape or sheet form; usually 6 to 12 lb per cu ft (96 to 192 kg per cu m) in density; used for thermal insulation and vibration control.

corking Same as cogged joint.

corkscrew stair A spiral stair.

cork tile A resilient material composed mainly of granulated bark of the cork oak tree and synthetic resins. The surface is finished either with a protective coat of wax, lacquer, or resin or with a film of clear polyvinyl chloride laminated to the top surface for easier maintenance; the natural surface requires waxing and buffing, the vinylized surface buffing only; set in mastic over wood or concrete subfloor.

corkwood See balsa.

corn. Abbr. for cornice.

corncrib, corn house A structure used for storing unhusked ears of corn; designed to provide adequate air circulation to ensure that freshly picked corn dries more or less uniformly during storage, so as to minimize spoilage. Found in a wide variety of sizes and shapes, but most often the sides slope inwardly so that the area is smaller at the bottom of the crib than at the top. Also called a corn loft.

corner In land surveying, a point established for marking the boundaries of landed property either by an actual survey or by agreement between neighbors. Monuments or other objects may serve to designate intersection points of the boundary lines.

corner bead, angle bead, angle staff, corner guard, corner molding, plaster bead, staff bead 1. Any vertical molding, usually a plain, filleted, or quirked bead, used to protect the external angle of two intersecting surfaces. 2. A strip of formed galvanized iron, sometimes combined with a strip of metal lath, placed on corners before plastering to reinforce them.

corner bead, 2

corner bit brace Same as angle brace, 3.

corner block 1. See corner return block. 2. A square, relatively flat wood block, often decoratively carved, placed at upper corners on each side of the wood framing around a door.

corner board A board which is used as trim on the external corner of a wood-frame structure and against which the ends of the siding are fitted.

corner brace A diagonal brace let into studs to reinforce corners of a wood-frame structure.

corner block, 2

corner board

corner brace

corner bracket A bracket which is connected to a doorframe jamb and head at the upper hinge corner, as a support for an exposed overhead door closer; used only on out-swinging doors.

corner capital Same as angle capital.

corner chimney A chimney whose face forms an angle across the intersection of two walls of a room, as in a fogón; occasionally called an angle chimney.

corner chisel A chisel having two cutting edges which meet at right angles; used for cutting corners of mortises.

corner clamp Same as miter clamp.

corner cracking Same as shrinkage cracking.

corner cupboard A cabinet built to fit into the corner of a room, its face forming a 45° angle with the adjacent walls.

corner drop A hand-carved or hand-turned wood ornament that is suspended from a corner of an overhanging second story of an early colonial American house. See pendant, 2 and turned drop.

corner drop suspended from a framed overhang

corner framing In a timber structure, a corner post that provides for nailing on the exterior or interior; often comprised of two or more studs joined together.

corner guard See corner bead.

corner lath See corner reinforcement, 2.

corner locking Any method of joining two timbers at a corner (for example, as in dovetailing) to form a rigid joint.

corner lot A lot of which at least two adjacent sides abut upon streets or public places, for their full length, which must not be less than a code-specified distance.

corner molding Same as corner bead, 1.

corner notch At a corner of a log cabin or log house, any one of several types of notches cut near an end of an exterior timber to form a rigid joint when mated with another appropriately notched timber set at right angles to it. See diamond notch, double-saddle notch, dovetail notch, half-dovetail notch, half-cut notch, halved-and-lapped notch, lap notch, log notch, round notch, saddle notch, single notch, single-saddle notch, square notch, V-notch.

corner pilaster An engaged pier or pillar, often with a capital and base, located at a corner of a building or colonnade.

corner post 1. In a timber structure, a post which is placed at a corner or return angle to provide for exterior or interior nailing. 2. A metal mullion member which connects two sheets of glass at an angle, forming a corner.

corner post, 1

corner reinforcement 1. In a knocked-down or welded doorframe assembly, the reinforcement at the junction of the head and jamb. 2. A strip of expanded-metal lath bent to form a 90° angle; used in an inside corner of a plaster wall, ceiling, etc., to prevent cracks in plastering. Also called corner lath. 3. See exterior corner reinforcement.

corner reinforcement, 2

corner return block, corner block A concrete masonry unit having a solid face at one end, as well as solid faces on the sides.

corner return block

cornerstone 1. A stone that forms a corner or angle in a structure. 2. A stone prominently situated near the base of a corner in a building, carrying information recording the dedicatory ceremonies, and in some instances containing or capping a vault in which contemporary memorabilia are preserved; a foundation stone.

cornerstone

corner stud Same as corner post.

corner tile A saddle-shaped tile used in covering the hip of a roof.

corner trap A trapdoor at the front of a theater stage, through which an actor can appear or disappear.

corner trowel In plastering or masonry, a hand-held trowel used to shape either inside or outside corners.

corn house Same as corncrib.

corniccione A principal cornice at the top of a façade.

cornice 1. Any molded projection which crowns or finishes the part to which it is affixed. 2. The third or uppermost division of an entablature, resting on the frieze. 3. An ornamental molding, usually of wood or plaster, running round the walls of a room just below the ceiling; a crown molding; the molding forming the top member of a door or window frame. 4. The exterior trim of a structure at the meeting of the roof and wall; usually consists of bed molding, soffit, fascia, and crown molding. For special types, see architrave cornice, boxed cornice, bracketed cornice, cavetto cornice, closed cornice, eaves cornice, modillion cornice, open cornice.

cornice

cornice lighting Lighting from sources which are shielded by a panel parallel to the wall and attached to the ceiling or to the upper edge of the wall and which distribute light over the wall.

cornice return The continuation of a cornice in a different direction, as at the gable end of a house.

cornice return

coro An elaborate choir, at times almost an independent building, commonly placed to the west of the transept in a Spanish cathedral.

corona The overhanging vertical member of a cornice, supported by the bed moldings and crowned by the cymatium; usually with a drip to throw rainwater clear of the building. Also see cornice.

corona

corona lucis A circle or hoop of lights or candles for a church, either suspended or supported on a stand.

coronarium In ancient Rome, stucco work applied to the decoration of a cornice or projecting molding.

coronet A pedimental or other decoration wrought in relief on a wall above a window or door.

CORP On drawings, abbr. for “corporation.”

Corporate style An austere style of industrial buildings used in New England during the early part of the 19th century; characterized by red brick walls in combination with white stone lintels; often gracefully proportioned.

corporation cock A valve which is placed in a water or gas service pipe of a building, near its junction with the public water or gas main.

corporation cock

corporation stop Same as corporation cock.

corps de logis The central part of a château, large house, or mansion, not including the wings or subordinate parts.

corpse gate Same as lych-gate.

corpsing A shallow mortise in a plaster finish coat.

CORR On drawings, abbr. for “corrugate” or “corrugated.”

corral An enclosure for livestock, commonly for horses.

corrected net fill The net fill corrected for the reduction in volume resulting from compaction.

corrective maintenance Maintenance that takes place after the occurrence of a failure, or in order to restore the item or piece of equipment to its normal working condition.

corredor In Spanish architecture, a long, narrow porch or arcade that often covers the entire front and/or one or more sides of a house; or a corridor in the house.

corridor 1. A long interior passageway providing access to several rooms. 2. A public means of access from several rooms or spaces to an exit. 3. An enclosed passageway that limits the means of egress to a single path of travel. Also see exit, passageway.

corrosion The deterioration of metal or of concrete by chemical or electrochemical reaction resulting from exposure to weathering, moisture, chemicals, or other agents in the environment in which it is placed.

corrosion inhibitor Any of a number of materials used to prevent the oxidation of metals; may be a coating applied to the surface, a paint undercoat, or an element alloyed with the metal.

corrugated aluminum 1. See corrugated metal. 2. When perforated, a facing for a sound-absorptive blanket in some acoustical ceiling constructions.

corrugated asbestos A siding or roofing material fabricated in the form of corrugated asbestos cement board.

corrugated fastener, joint fastener A steel fastening device used to join corner pieces in rough carpentry; one side of a small corrugated strip is sharpened so that it may be driven into the two wood pieces to be joined; used only where appearance is not important.

corrugated fastener

corrugated glass Glass which has been corrugated to provide greater diffusion of light.

corrugated iron Sheet steel (usually galvanized) which has been fabricated as a corrugated metal.

corrugated metal Sheet metal which has been drawn or rolled into parallel ridges and furrows to provide additional mechanical strength; aluminum and galvanized sheet steel are widely used.

corrugated roofing A roofing material in sheet form, usually of galvanized metal or cement asbestos, shaped into alternate ridges and valleys.

corrugated-roofing nail Same as roofing nail.

corrugated tubing Same as flexible seamless tubing.

corsae In Classical Roman architecture, fillets or moldings used to decorate the external face of a marble doorpost.

corseria A passageway, from one tower to another, along the walls of a medieval town or in a castle.

cortile An interior courtyard enclosed by the walls of a palazzo or other large building; often arcaded.

cortina In Spanish, literally, a curtain. In Spanish architecture or its derivatives, corbeled stonework directly below a balcony or windowsill.

corundum A hard, abrasive mineral, principally aluminum oxide, applied to a surface to make it non-slippery; for example, on the walking surface of a ramp.

cosine law See Lambert’s cosine law.

Cosmati work Polychromatic patterns of stone, glass, or gilding set in marble; commonly applied in Italian Romanesque architecture.

cost adjustment On a construction project, a change (for any reason) in the total contract cost which is agreed to by the owner, the architect, and the contractor.

cost-benefit analysis An analysis of a construction contract with the objective of identifying all the included costs and evaluating their benefits.

cost breakdown See schedule of values.

cost consultant A professional who, by training and experience, provides expert advice on construction costs.

cost control Management of a project to ensure that construction costs do not exceed the budgeted amount.

cost of construction The sum of all direct and indirect costs of construction; generally categorized as equipment costs, job overhead costs, operating overhead costs, material costs, plant costs, and profit.

cost of light See lighting cost.

cost-plus-fee agreement An agreement under which the contractor (in an owner-contractor agreement) or the architect (in an owner-architect agreement) is reimbursed for his direct and indirect costs and, in addition, is paid a fee for his services. The fee is usually stated as a stipulated sum or as a percentage of cost.

cost proposal The response made by a contractor who is proposing anticipated changes in the cost of construction after the architect has issued a proposal request.

cot A small house or cottage.

cot bar A glazing bar which connects the radial bars of a fanlight.

cotloft (Brit.) See loft, 2.

cottage 1. A relatively small house, often in a village, in the countryside, in a suburb, or at the seashore. 2. A small vacation house. 3. A dwelling, often temporary, that provides only basic shelter. 4. An imposing mansion (as found in Newport, Rhode Island). Also see banquette cottage, Cajun cottage, Chicago cottage, Dutch cottage, Normandy cottage, one-and-one-half bay cottage, one-bay cottage, one-room cottage, palma cottage, prairie cottage, raised cottage, tidewater cottage, two-bay cottage.

cottage hospital 1. An institution in which patients are housed in relatively small, homelike units, each providing eating and living space for a small group. 2. (Brit.) A small hospital served by local nonspecialist physicians.

cottage orné A small, picturesque house in a rural or country setting, primarily in the late 18th and early 19th centuries. Some cottages were so classified because straight tree trunks were used as columns and selected parts of tree branches were used as brackets; others were placed in this category merely because their ornamentation was said to create a picturesque effect.

cottage roof A roof which has common rafters that rest on wall plates and are joined at their upper ends in a ridge; no principal beams are used.

Cottage style house 1. A style of domestic architecture, usually of wood construction, popularized in the 19th century, primarily by the pattern books of architects Andrew Jackson Downing (1815–1852) and Alexander Jackson Davis (1803–1892); usually included many of the following characteristics: an asymmetric plan, walls of board-and-batten construction, balconies, decorative chimneys, steeply pitched roofs, and bay windows. 2. A loose term infrequently applied to a bungalow.

Cottage style house

cottage window A double-hung window having its upper sash smaller than the lower sash; the upper pane is often decorated.

cotter A beveled piece of wood or steel, used as a wedge for fastening.

cotter pin A metal pin used for fastening; the split ends which project beyond the pin hole are bent back from the axis of the pin.

cotter pin: above; below, installation

cotton mats Cotton-filled quilts fabricated for use as a water-retaining covering in curing concrete surfaces.

coulisse, cullis 1. A piece of channeled or grooved timber, as one in which a frame slides. 2. An area backstage in the theater, esp. between two wing flats.

council school (Brit.) An elementary or secondary school supported by public taxes; similar to public school in US.

count In wire cloth, the number of openings per linear inch.

counter 1. A long horizontal surface used in stores, shops, banks, etc., for display of goods, for work-top areas, or for business transactions. 2. The top or working surface of the base of a kitchen cabinet.

counter apse An apse which is opposite another apse. Many such double apses have a crypt below the western apse.

counter arch An arch used to counteract the thrust of another arch.

counterbalanced window A double-hung window constructed so that the weights of the upper and lower sashes balance each other.

counterbalance system Same as counterweight system.

counter batten A furring strip which is below, and at right angles to, the battens.

counterbore To enlarge a hole to receive the head of a bolt or a nut.

counterbrace A brace which counteracts the strain of another brace, as a web member of a truss.

counterbracing A system of counterbraces.

counterceiling Same as false ceiling.

counter cramp A construction joint used to join segments of built-up stair stringers or counter tops. Slotted strips of wood are secured along the face of the stringers at the joint. Thin folding wedges are inserted in the slots to align the strips and thereby tighten the joint.

counterflashing, cover flashing, cap flashing A strip of sheet metal, often built into masonry and turned down over other flashing; used to prevent water from entering the joints and the exposed upturned edges of base flashing on a roof.

counterflashing

counterfloor See subfloor.

counterfort In masonry structures, a buttress, spur wall, pier, or projecting portion, extending upward from the foundation or from the inner face of a basement, abutment, or retaining wall to provide additional resistance to thrust.

counterfort wall A cantilever wall that is reinforced with counterforts or buttresses.

counter gauge Same as mortise gauge.

counterguard In a medieval fort, a structure placed in a ditch in front of a bastion to provide additional protection.

counter-imbrication See contre-imbrication.

counterlathing See cross-furring.

counterlight A light or window directly opposite another.

countermure A wall between the inner wall and outer wall of a fortification, either to provide additional defense or as an aid to the besieger.

counter-relief A carving, casting, or embossed design which is sunk below the general surface area.

counterscarp The face of the ditch of a fortress sloping toward the defender.

counterscarp wall The revetment of a counterscarp, usually made of stone or brick, but occasionally of timber.

countersink A boring bit having a conical-shaped cutter; used to make a depression to receive the head of a screw or bolt so that it does not protrude above the surface.

countersink

countersunk bolt A bolt having a circular head with a flat top and a conical bearing surface which tapers in from the top; when in place, the head is flush-mounted.

countersunk bolt

countersunk rivet A rivet used in countersunk holes in which the point, while hot, is hammered down to fill the countersinking.

countervault An inverted arch.

counterwall 1. A wall of a building that is adjacent to, but separated from, the end wall of a building; party wall. 2. Same as countermure.

counterweight 1. A weight that just balances another weight. 2. In a theater stagehouse, a weight (usually of iron, sand, or shot) used to balance suspended scenery, or the like.

counterweight arbor A movable frame in which are stacked the modular counterweights of a counterweight system.

counterweighted window A window having sashes, each of which is counterbalanced with a weight.

counterweight safety See elevator car safety.

counterweight system A permanent, overhead, theater stage rigging system; used to raise or lower scenery or lighting equipment which is counterbalanced by counterweights that ride in vertical tracks at the side of the stage.

counting house A building once used primarily for accounting and bookkeeping.

country seat A rural residence of some importance.

couple Two equal and opposite parallel forces, with different lines of action, tending to produce rotation of a body; their moment equals the product of the magnitude of one of the forces and the perpendicular distance between them.

couple-close, close couple A pair of opposite rafters which are connected by a collar beam or tie beam and are tied together at the apex.

coupled arcade An arcade supported on coupled columns.

coupled columns Two closely spaced columns that form a pair. (See illustration p. 270.)

coupled pilasters Two closely spaced pilasters forming a pair.

coupled windows Two closely spaced windows which form a pair. (See illustration p. 270.)

coupler A metal hardware device used to join frames and braces of tubular metal scaffolding.

coupled columns

coupled windows

couple roof, coupled roof A double-pitched roof, usually of narrow span, in which opposite rafters are not tied together; the walls resist the outward thrust.

couples Terminology once used to designate a pair of rafters.

coupling A short internally threaded section of pipe, used to join two pipes or conduits.

coupling

coupling pin A pin, 1 which is used to connect lifts or tiers or formwork scaffolding vertically.

cour d’honneur The forecourt of a building, especially a monumental forecourt.

course 1. A layer of masonry units running horizontally in a wall or, much less commonly, curved over an arch; it is bonded with mortar. 2. A continuous row or layer of material, as shingles, tiles, etc. 3. In concrete construction, one of several horizontal layers making up a lift, 5. For specific types, see band course, base course, belt course, blocking course, bond course, coping course, corbel course, dog-tooth course, masonry course, random course, sill course, springing course, staggered course, stringcourse, tumbling course.

course, 1

coursed ashlar, range masonry, range-work, regular coursed rubble Ashlar masonry in which the stones are of equal height within each course; all courses need not be of the same height.

coursed masonry, course work Masonry construction in which the stones are laid in regular courses, not irregularly as in rough or random rubble.

coursed pattern A pattern formed by shingles that are laid in regular horizontal rows of equal height, each row overlapping the row below, with the vertical joints of one row usually falling approximately midway between those of the row below.

coursed rubble Masonry construction in which roughly dressed stones of random size are used, as they occur, to build up courses; the interstices between them are filled with smaller pieces, or with mortar.

coursed square rubble Same as random ashlar.

coursed rubble

coursed veneer In stone masonry, the use of veneer stones having equal height to form each continuous course, with horizontal joints extending the full length of the façade; the vertical joints are broken so that no two vertical joints form a continuous line.

course-grained Said of wood from a tree having wide, conspicuous annual rings.

course work See coursed masonry.

coursing joint A horizontal or arched mortar joint between two courses of masonry in a wall or arch.

court 1. An open, uncovered, and unoccupied space partially or fully surrounded by walls or buildings. 2. A courtroom. 3. Residence of a dignitary or member of royalty and its enclosed grounds.

courthouse 1. A building in which are contained rooms for courts of law, judges’ chambers, offices of clerks of court, and, sometimes, other official offices. 2. A building containing county administrative offices, often including the county jail.

courtroom The main room in a courthouse where the judge presides.

courtyard An open area that is partially or fully enclosed by one or more buildings and/or by walls. Courtyards that are enclosed or partially enclosed by walls are sometimes referred to as patios. Also see placita.

coussinet 1. The stone which is placed on the impost of a pier to receive the first stone of an arch. 2. The part of the front of an Ionic capital between the abacus and echinus.

cove A concave surface or molding, especially placed at the transition from a wall to the ceiling, or from a wall to the floor.

cove base A congé, 2.

cove bracketing A series of wood brackets or the framing set to receive the laths for a cove, as in constructing a cove ceiling.

coved base A trim piece at the base of a wall forming a concave rounded intersection with the floor.

coved ceiling A ceiling having a cove at its intersection with the wall.

cove ceiling

coved eave That part of a roof that projects beyond the exterior wall, the underside of which is covered with a concave surface so that the rafters are not visible.

coved eave

coved vault, cloistered arch, cloistered vault A vault, 1 composed of four quarter-cylindrical surfaces or coves, meeting in vertical diagonal planes, the axial sections of the vault being arched, and the horizontal courses diminishing in length from spring to crown. (See illustration p. 272.)

cove header brick, cove header A brick having one end that is molded or shaped with a cove or concave curve.

coved vault

cove lighting Lighting from sources which are out of sight, atop a wall molding; shielded by a ledge or horizontal recess, and which distribute light over the ceiling and upper walls.

covemold frame A steel doorframe having a cross section which is similar in shape to a wood doorframe with a cove molding at its outer edge.

cove molding, cavetto A molding having a concave face; often used as trim.

covenant See restrictive covenant.

covenanter door Same as Christian door.

cover 1. In reinforced concrete, the least distance between the surface of the reinforcement and the outer surface of the concrete. 2. That part of a tile or shingle which is covered by the next course. 3.The concrete (or concrete-like material) which covers steel reinforcement to protect the steel from possible fire damage or corrosion.

coverage 1. A measure of the area over which a gallon of paint may be spread at a given thickness, usually expressed as square feet per gallon at 1 mil dry film. 2. The amount of surface that can be covered by a particular amount of roofing material. 3.The ratio of the area of the footprint of a building to the total area of the site on which it is located.

cover block Same as spacer.

cover coat In ceramics, the layer of porcelain enamel normally applied over a ground coat.

covered bridge A roofed bridge, typically constructed of heavy timbers and trusses, enclosed or partially enclosed on its sides; especially found in regions having heavy snowfall.

covered joint A lap joint.

covered shaft An interior enclosed space that extends through one or more stories of a building, connecting openings in successive floors, or the floors and roof; must be covered at the top.

cover fillet See cover molding.

cover flange Same as escutcheon.

cover flap A hinged flap which covers boxing shutters.

cover flashing See counterflashing.

covering capacity A term now replaced by hiding power.

covering power See hiding power.

cover molding, cover fillet A wood strip covering a joint, as between sections of paneling.

cover plants Plants, usually low-growing, used to cover soil so as to prevent its erosion.

cover plate 1. A plate fastened on the flanges of a girder to give it additional cross section. 2. A top or bottom plate of a chord, 1; also called flange plate.

coverport In a medieval fort, a small defensive structure that provides protection for the front of a gate.

coverstone A flat stone which is laid on a steel beam or girder and serves as a foundation for the masonry laid on it.

cover strip A thin strip used to cover a butt joint.

cover tile Same as imbrex.

covertway A walkway atop a counterscarp.

coving 1. Coves. 2. Vertical outward curve of an exterior wall, esp. to meet eaves or a jetty. 3. A concave molding along a rood beam to support a loft or gallery. 4. The curved or splayed jambs of a fireplace which narrows toward the back.

cow barn, cow house, cow shed A dependency used to house cattle.

cowl A protective hood on a vertical pipe (such as a soil stack or vent pipe); used to exclude rainwater and snow.

cownose-brick A brick having a semi-circular end.

cp Abbr. for candlepower.

CP On drawings, abbr. for cesspool.

CPFF Abbr. for “cost plus fixed fee.”

CPM Abbr. for critical path method.

cpm Abbr. for “cycles per minute.”

cps Abbr. for “cycles per second”; same as Hz, abbr. for hertz.

C-purlin See C-section.

CPVC Abbr. for “chlorinated polyvinyl chloride.”

CR 1. Abbr. for “cold-rolled.” 2. Abbr. for “ceiling register.”

Cr Abbr. for “cross.”

crab 1. A short shaft or axle, mounted on a frame, having squared ends to receive hand cranks; used to wind up a rope carrying a load. 2. See crocket.

crabwood See carapa.

crack A building defect consisting of complete or incomplete separation within a single element or between contiguous elements of constructions.

crack-control reinforcement Steel reinforcement in concrete construction to prevent cracks or to limit them to small, uniformly distributed ones.

cracked section A section which is either designed or analyzed on the assumption that concrete has no resistance to tensile stress.

cracking See crazing, alligatoring, crawling, hairline cracking.

cracking load That load which causes the tensile stress in a structural concrete member to exceed the tensile strength of the concrete.

crackle In painting, a paint or lacquer designed to develop a network of fine cracks when applied over a softer undercoat.

crack length The total length of all cracks measured along the outer edges of window frames and the inner faces of stops or beads around sash; used to determine the air infiltration of the entire window when the air-infiltration rate is known.

cradle 1. See chimney foundation. 2. The structural support for a pipe which is placed below and to one side of the pipe.

cradle roof A barrel roof, 1.

cradle vault Same as barrel vault.

cradling Timber framing for supporting the lath and plaster or masonry of a dome or vaulted ceiling.

Craftsman style A domestic architectural style in America in the first few decades of the 20th century, greatly influenced by the Arts and Crafts movement. Houses in this style were usually characterized by: a nonsymmetrical façade, typically sheathed with stucco, wood clapboard, or wood shingles, and less often with board and batten, brick, concrete block, or stone; often, masonry walls on the first story and clapboard or wood shingles on the second story; occasionally, a battered foundation; a gabled porch, recessed or trellised, facing the street; commonly a porte cochère at one side of the porch; usually a low to moderately pitched front-gabled roof; exposed roof rafters, beams, false beams, or triangular knee braces inserted as decorative elements under the gables; gabled dormers or shed dormers with exposed beams; double-hung windows or heavily framed casement windows. The interior commonly featured a high wainscot that was integrated with the doors and windows as part of the structural decoration. The stairway from the living room to the floor above was often an important design element.

Craftsman style: upper hall of a residence

cragstone Same as corbel, 2.

crail work Ornamental ironwork.

cramp 1. A U-shaped metal fastening to hold adjacent units of masonry together, as in a parapet or wall coping; a cramp iron. 2. A rectangular frame, with a tightening screw, used to compress joints between wood pieces during gluing. 3. A device for holding a frame in place during construction.

cramp, 1

cramp iron A cramp, 1.

crampon A lifting device (for rocks, timbers, etc.) having two steel spikes which grasp the load.

crandall A hammer-like tool having a number of sharp, pointed steel rods which are held in a slot at the end of a handle; used for dressing stone.

crandall

crane 1. A machine for lifting or lowering a load and moving it horizontally, in which the hoisting mechanism is an integral part of the machine; classified by mounting, by boom configuration, and by lifting capacity. 2. See fireplace crane.

crane

crane boom See boom, 2.

crane gantry See gantry crane.

crank arm operator Same as roto operator.

crank brace Same as brace, 3.

crapaudine door, center-pivoted door A door which rotates on pivots set into the lintel and the doorsill rather than about one vertical edge.

crash bar The cross bar of a panic exit device; serves as a push bar to actuate the panic hardware.

cratchet An upright tree trunk having a natural fork at its upper end; the Y of the fork is used to support the ridgepole of the roof.

cratchet

cratering The formation of small craters in a paint film, caused by bursting bubbles of air which were trapped during application.

crawl The movement of paint in a wet paint film that does not remain evenly spread but redistributes itself after application, usually as a result of an imperfect bond with the surface.

crawl boards Boards placed on roofing that are intended to protect it against heavy foot traffic.

crawler tractor An engine-driven vehicle that travels on segmented roller-chain tracks designed to reduce ground pressure and increase traction in loose footing; powesed by a gasoline or diesel engine.

crawler tractor

crawling 1. A defect in porcelain enamel, appearing as agglomerates or irregularly shaped “islands.” 2. A parting and contraction of the glaze on the surface of ceramic ware during drying or firing, resulting in unglazed areas bordered by coalesced glaze.

crawling board A plank with cleats spaced and secured at equal intervals, for use by a worker on roofs; not designed for transporting material.

crawl space 1. Any interior space of limited height, but sufficient to permit workmen access to otherwise concealed ductwork, piping, or wiring. 2. In a building without a basement, an unfinished accessible space below the first floor which is usually less than a full story in height; normally enclosed by the foundation wall. 3. A creep trench.

crawl space, 2

crawlway A crawlspace having one dimension that is many times larger than the other two.

crazing, cracking, craze cracks Fine, random cracks or fissures in a network on or under a surface of plaster, cement, mortar, concrete, ceramic coating, or paint film; caused by shrinkage.

crazy paving Randomly set paving stones having neither a definite shape nor a fixed size.

crease tile See crest tile.

creasing 1. One or more courses of tiles or bricks laid upon the top of a wall or chimney with a projection of 1 to 2 in. (2.5 to 5 cm) for each course over the one below, to throw off water; if there is coping, it is placed above the creasing. Also called a creasing course, tile creasing. 2. A layer of slates or of metal over a projecting string-course or window cap, serving as a flashing to prevent the infiltration of moisture.

creasing course Same as creasing, 1.

credence A small stand or shelf near an altar to hold the elements of the Eucharist: church vessels, service books, etc.

credence

creekstone A quartzite stone that has been worn smooth by the action of flowing water.

creep 1. The continuing, time-dependent part of strain resulting from stress; the permanent and continuing dimensional deformation of a material under a sustained load, following the initial instantaneous elastic deformation. 2. Slow movement of rock debris or soil, usually imperceptible except in observations of long duration. 3. In structures, particularly of concrete, permanent deflection of structural framing or structural decking resulting from plastic flow under continued stress. 4. In roofing, permanent elongation or shrinkage of a roofing membrane resulting from thermal or moisture changes. 5. The flow of water along the interface between a structure and the surrounding soil or rock foundation.

creeper 1. A brick in the wall adjacent to an arch, cut to conform to the curvature of the extrados. 2. (pl.) Same as crocket.

creep strength The stress that produces a given rate of creep at a specified temperature.

creep trench A low underfloor horizontal passageway, usually less than 3¼ ft (1 m) high. Also see crawl space.

crematory, crematorium A building for the incineration of the human dead.

cremone bolt, cremorne bolt A type of hardware for locking French windows or the like; a rotating handle actuates sliding rods which move in opposite directions, extending from the edges of the window into sockets that are fixed in the frame.

cremorne bolt See cremone bolt.

crenation One of a series of rounded projections or teeth forming an edge.

crenel, crenelle An open space between the merlons of a battlement.

B, crenel

crenelated, crenellated 1. Having battlements. 2. Bearing an embattled pattern of repeated indentations.

crenelated

crenelated molding, crenellated molding, embattled molding A molding notched or indented to represent merlons and embrasures in fortification.

crenelated molding

crenelet 1. A small crenel, whether in an actual battlement or in a decorative design imitating one. 2. A small arrow loop.

crenellation See battlement.

crenellation

Creole house A house developed by the Creoles (i.e., French-speaking persons of European ancestry born in the Gulf Coast or environs in the early 18th century) designed to provide reasonable comfort under the local conditions of high temperature and high humidity; usually rectangular in plan, with one or two rooms, a garret overhead; a bonnet roof or a roof having a single slope on each side of a central ridge; usually a raised house surrounded (or partially surrounded) by a full-length porch along one or both sides of the house; the rooms are entered through French doors from the porch. The floor on which the family lived was raised well above ground level to improve the air circulation. Compare with Cajun cottage.

Creole house

creosote An oily liquid obtained by distilling coal tar; used to impregnate wood (as a preservative) and to waterproof materials. Also called dead oil and pitch oil.

crepido A raised base on which other things are built or supported, as an ancient Roman temple or altar.

crepidoma The base courses (a stepped platform) of a classical (esp. Greek) temple. Also see stylobate.

crescent A building or series of buildings whose façades follow a concave arc of a circle or ellipse in plan.

crescent arch A horseshoe arch.

crescent truss A truss in which the top chord and the bottom chord are either both curved upward or both curved downward; having different radii of curvature, the chords intersect at the ends, forming a crescent profile; between the chords is a web.

crescent truss

cresset stone In a medieval church, a stone which has been hollowed out to hold oil. A wick set in the oil, when lighted, provides illumination for the surrounding area.

cress tile See crest tile.

crest 1. A finial. 2. An ornament of a roof, a roof screen, wall, or aedicula, generally rhythmic and highly decorative, and frequently perforated; cresting.

crest, 2

cresting See crest, 2.

crest tile, crease tile, cress tile 1. Tile which fits like a saddle on the ridge of a roof. 2. Tile forming a crest, 2.

CRI Abbr. for “color rendering index.”

crest tiles, 1: b

crest tiles, 2

crib 1. A lining of a shaft, such as a framework of timbers. 2. A framework constructed of squared timbers, steel, or concrete members; used as a retaining wall or to provide support for construction above. 3. A partial enclosure for storing hay, corn, or the like; also see corncrib.

crib wall A framework of wood, concrete, or metal members used as a retaining structure; see cribbing, 2.

crib barn A crudely constructed barn once used to house animals or to store agricultural products; usually timber-framed, but sometimes built of logs. If constructed with one storage space, it was called a single-crib barn; if two storage spaces, a double-crib barn; if four storage spaces, a four-crib barn.

cribbing 1. A system of cribs, 2. 2. A framework of wood, concrete, or metal members which form open bins that are filled with crushed rock or pervious soil; used as a retaining structure for an earth embankment. 3. A framework of timber mats, steel members or plates, etc., used as a support for mobile cranes, or the like.

cribbled Covered with dots, raised or sunk (describing a surface or background). Also see scumbled.

crib test A test for rating combustible properties of treated wood which is exposed to fire.

cribwork 1. A construction of timber made by placing horizontal beams one above the other and fastening them together, each layer being at right angles to those above and below it. 2. Same as cribbing.

crick A small jackscrew.

cricket, saddle A small saddle-shaped projection on a sloping roof; used to divert water around an obstacle such as a chimney.

cricket

crimp 1. To bend or warp. 2. To offset a structural steel member so that it will fit over the flange of another member.

crimped copper Copper in sheets or strips having small transverse corrugations to provide for expansion, to increase rigidity, or to serve as ornamentation.

crimped wire A wire having a series of small curves in it; these deformations are provided to increase the capacity of the wire to bond to concrete.

crimping A process similar to corrugating, but providing a surface (essentially flat) with regularly spaced small ridges.

crinkle-crankle (Brit.) A serpentine wall, esp. in the 18th century. Same as serpentine wall.

crinkled On a porcelain enamel surface, a textural effect having the appearance of fine wrinkles or ridges.

crinkling See wrinkling.

cripple 1. In a building frame, a structural element that is shorter than usual, as a stud above a door opening or below a windowsill. 2. In roofing, a bracket that anchors at the ridge line and carries scaffold platforms for roofing workers.

cripple rafter A jack rafter.

cripple stud A cripple, 1.

cripple wall A stud wall less than a full story in height.

cripple window (Brit.)A dormer window.

crippling load British term for buckling load.

criss A jig for forming crest tiles.

criterion 1. A standard or rule on which a decision or judgment may be based, forming the basis for the establishment of acceptable limits of environmental conditions in buildings. 2. An established code, measure, norm, or rule upon which a decision may be based.

cripples, 1

critical angle An angle of pitch of stairs or a ramp which is considered uncomfortable and unsafe if exceeded; this angle is 50° for stairs and 20° for ramps.

critical density That unit weight of a saturated granular material above which it will gain strength and below which it will lose strength when subjected to rapid deformation.

critical height The maximum height at which a vertical cut in a cohesive soil will stand unsupported.

critical level The setting on a backflow preventer or vacuum breaker which determines its minimum permitted elevation above the flood-level rim of the fixture or receptacle served.

critical load The load, 1 on a member or structure at which failure is likely to occur.

critical path The longest irreducible sequence of work activities which determines the minimum duration of a construction project.

critical path method, CPM A system of project planning, scheduling, and control which combines all relevant information into a single master plan, permitting the establishment of the optimum sequence and duration of operations; the interrelation of all the efforts required to complete a construction project are shown; an indication is given of the efforts which are critical to timely completion of the project.

critical section In structures, that section or position where failure is most likely to occur.

critical slope The maximum angle with the horizontal at which a sloped bank of soil of given height will stand unsupported.

critical speed The angular speed of rotating machinery at which excessive vibration is produced; at this speed the periodic disturbing force coincides with a mechanical resonance of the shaft and/or of the machinery or its supports.

critical temperature 1. The temperature at which a steel structure cannot carry the service load for which it was designed because of softening of the steel that occurs when it is heated significantly. 2. Same as self-ignition temperature.

critical velocity Of a liquid flowing in a pipe, the velocity at which the flow changes from laminar flow to turbulent flow.

critical void ratio That void ratio which corresponds to the critical density.

CRMS Abbr. for cold-rolled mild steel.

crocidolite Same as riebeckite asbestos.

crocket In Gothic architecture and derivatives, an upward-oriented ornament, often vegetal in form, regularly spaced along sloping or vertical edges of emphasized features such as spires, pinnacles, and gables.

crocket

crocket capital A capital having a series of crockets.

crocking A paint defect that permits color to be removed from a surface by rubbing.

crock tile A glazed clay drain tile, sometimes with bell-shaped ends.

crocodiling See alligatoring, 1.

croft An undercroft.

croisette Same as crossette.

cromlech 1. A monument of prehistoric or uncertain date consisting of an enclosure formed by huge stones planted in the ground in a circle. 2. A dolmen.

crook 1. The warp of a board edge from a straight line drawn between the two ends; also called edgebend or spring. 2. A piece of timber so warped; a knee.

crook rafter A knee rafter.

crop, crope A bunch of foliage worked or sculptured at the top of a spire, finial, or similar decorative member, and having a resemblance to the top of a plant.

croquet Same as crocket.

crosette Same as crossette.

cross 1. An object consisting primarily of two straight or nearly straight pieces forming right angles with one another; the usual symbol of the Christian religion. 2. A monument or small building of any kind surmounted by a cross, 1, as a market cross. 3. A pipe cross.

cross, 3

cross aisle 1. In a church, a transverse aisle between pews. 2. In an auditorium, an aisle usually parallel to rows of seats, connecting other aisles or an aisle and an exit.

cross-and-bible door Same as Christian door.

crossband, crossbanding, cross core 1. In plywood, a veneer sheet whose grain is at right angles to the face veneer. 2. Any decorative band whose grain is perpendicular to the principal surface. (See illustration p. 280.)

cross bar In a grating, one of the connecting bars which extend across bearing bars, usually perpendicular to them; where they intersect the bearing bars, they are welded, forged, or mechanically locked to them.

crossbanding, 1

cross bar centers In a metal grating, the distance between centers of the cross bars.

cross batten A batten, 2.

cross beam, crossbeam 1. A large beam between two walls. 2. A girder that holds the sides of a building together. 3. Any beam that crosses another. 4. A strut between the walings on opposite sides of an excavation. 5. A beam which runs transversely to the center line of a structure. 6. Any transverse beam in a structure, such as a joist.

cross-bedding In sedimentary rocks, inclined laminations or bedding which lends textural and color pattern to building stone of such material.

cross bond A masonry bond in which courses of Flemish bond alternate with courses of stretchers; the joints in the courses above and below the stretchers are opposite the centers of the stretchers.

cross bond

cross brace Same as X-brace.

cross bracing 1. Any system of bracing in which the diagonals intersect; also called X-bracing. 2. Horizontal timbering which extends across an excavation so as to support a cofferdam or sheathing. 3. Braces that cross from one column to the next to increase the load-bearing capacity of the combination.

cross break Separation in wood in a direction perpendicular to the normal grain direction.

cross bridging, diagonal bridging, herringbone strutting Diagonal bracing (in pairs) between adjacent floor joists to prevent the joists from twisting.

cross bridging

cross-church A cruciform church; one having a cross-shaped ground plan.

cross-connection 1. A connection between two otherwise separate piping systems, one containing potable water and the other water which may be contaminated. 2. In a fire-protection system, a piping connection from a siamese connection to a standpipe or to a sprinkler system.

cross core See crossbanding.

crosscut Cut at right angles to the grain.

crosscut saw A saw adapted by its filing and setting to cut across the grain of wood rather than with the grain.

crosscut saw with details showing saw teeth

crossette 1. A decorative embellishment, such as a molding around one corner of a door, window, or fireplace opening, that somewhat resembles a squared-off ear; especially popular during the latter half of the 18th century; also called a dog’s ear. 2. A small projecting part of a voussoir (arch stone), which hangs upon an adjacent stone.

crossettes, 1

crossettes, 2

cross fall On the surface of the ground, the gradient across the width of a building.

cross fire, cross figure A fiddleback grain pattern.

crossflow filtration A water filtration process in which a semipermeable membrane is used to separate waterborne contaminants from the water. The bulk solution flows over and parallel to the filter surface, and under pressure, a portion of the water is forced through the membrane filter.

crossflow filtration

cross-furring, brandering, counterlathing Strips, flat bands, or fillets which are applied on the undersides of joists to which lath (for plastering) is nailed; usually attached perpendicular to the main framing members.

cross gable A gable which is set parallel to the ridge of the roof.

cross gables

cross-garnet hinge A hinge shaped like the letter T; the longer part is fastened to the door leaf and the shorter to the frame.

cross girder Any beam which unites longitudinal girders.

cross grain Grain in wood not parallel with the long dimensions, or irregular gnarled grain.

cross grain

cross-grained float A wooden float having the grain of the wood parallel to the short side of the float. Used for leveling and scouring the surface of plaster or cement.

crosshairs Crossed wires or etched lines on a reticule in the focal plane of the telescope of a surveying instrument.

cross house, cross-plan house A masonry house having a cruciform plan (i.e., shaped like a cross); especially found in colonial Maryland and Virginia. At the front of the house, entry was through a front door in a two-story extension in the transverse direction of the cross; at the rear of this extension was an enclosed porch on the ground floor containing a small, steep stair leading to a room above. Meals were usually prepared in an outkitchen near the house.

cross house

crossing 1. In a church, the place where the nave and chancel cross the transept. 2. A painting technique whereby freshly applied paint is rebrushed at right angles to the direction of application and then rebrushed at right angles again to provide even distribution of paint over the surface. 3. Same as crossbanding.

cross-in-square plan Said of the plan of an early Christian church that was divided into nine bays; the central bay was a large square with a dome over its center; the four corner bays were each small, domed, and square in plan; the remaining four bays were barrel vaults.

cross joint See head joint.

cross-laminated Laminated so that some layers of material are oriented at right angles to the remaining layers with respect to the grain or to the direction in which tension is greatest.

crosslap joint A joint connecting two wood members which cross each other; half the thickness of each is cut away so that the thickness at the joint is the same as that of each member.

crosslap joint

crosslight Light received from windows at right angles to each other.

crosslighting Lighting an object from two opposite sides.

crosslot bracing The horizontal compression members that run from one side of an excavation site to the other; used to support sheeting.

cross main Pipes which supply the branch lines, 2, either directly or through risers.

cross nogging Bracing between common joists which is arranged in a herringbone pattern.

crossover 1. A connection between two pipes in the same water-supply system, or between two water-supply systems containing potable water. 2. A pipe fitting shaped like the letter U with the ends turned outward; used where one pipe crosses another in the same plane; also called a crossover fitting. 3. In an auditorium, a passage which usually parallels the rows of seats, forming a connection between aisles. 4. At the rear of a stage in a theater, a passageway that permits an actor to pass from one side of the stage to the other side without being seen by the audience.

crossover fitting See crossover, 2.

cross panel A rectangular panel with its longest dimension in a horizontal direction.

cross passage A passageway across one end of an open hall, 2 that separates the hall from the area that serviced the hall.

cross peen hammer A hammer having a wedge-shaped peen.

cross peen hammer

crosspiece Any piece of timber or beam crossing from wall to wall or running from one part to another.

cross quarters A cross-shaped ornamental flower in tracery.

crossrail In a panel door, any horizontal member other than those at the top and bottom of the door.

cross rib Same as arch rib.

cross riveting Same as staggered riveting.

cross runner In a suspended acoustical ceiling, a secondary member of the suspension system. Also see cross-furring.

cross seam A seam that is perpendicular to the long edge of a roll of carpeting.

cross section A representation of a building, or portion thereof, drawn as if it were cut vertically to show its interior; often taken at right angles to the longitudinal axis of the building.

cross-sectional area See net cross-sectional area.

cross-sill A sill, 1 oriented in a direction perpendicular to the length of the structure.

cross slit In a medieval fortification, an arrow loop that has a narrow horizontal opening permitting a soldier to fire his weapon at the enemy.

cross slope Of a surface, the slope that is perpendicular to the direction of travel. Compare with running slope.

cross springer 1. The diagonal arch of a ribbed groin vault. 2. A transverse rib of a groined roof.

crosstalk Undesired signals in one electrical circuit as a result of electrical coupling with another circuit.

cross tee A light-gauge metal member, similar in shape to an inverted T; used to support the abutting ends of form boards in insulating concrete roof constructions.

cross tongue A tongue of wood (either cross-grained or plywood) used to join two timbers in a tenoned frame to provide additional strength.

cross valve A valve fitted on a transverse pipe between two parallel pipes in order to provide flow between them.

cross vault A vault formed by the intersection at right angles of two barrel vaults.

cross vault

cross ventilation The circulation of fresh air through open windows, doors, or other openings, which are in opposite sides of the room or rooms being ventilated.

crosswalk An area across a street or road esp. designated for pedestrians by special markings or paving materials.

cross-wall construction See box frame, 1.

cross welt, transverse seam In flexible-metal roofing, a seam between sheets; usually parallel to the gutter or to the ridge.

cross window A window in which the combination of a single mullion and a transom presents the appearance of a cross.

cross-wire weld A weld made between crossed wires or bars.

crotch The point where a tree branch joins the trunk.

crotchet Obsolete term for crocket.

crotch veneer Wood veneer cut from the crotch of a tree; often exhibits unusual and decorative grain patterns. Also see curl.

croud Same as crowde.

crowbar, crow A steel bar, one end of which is flattened; sometimes slightly bent; used for heavy prying, and as a lever for moving heavy objects.

crowde A crypt or cellar, especially of a church.

crowfoot 1. Colloquial term for stylolite. 2. A V-shaped marking on an architectural or engineering drawing, the apex of which indicates a reference point or the limit of a dimension.

crowfooted Having corbiesteps.

crowfooted gable, crow gable Same as corbie gable.

crow gable See corbie gable.

crown 1. Any upper terminal feature in architecture. 2. The top of an arch including the keystone, or of a vault. 3. The corona of a cornice, sometimes including elements above it. 4. The camber of a beam. 5. The central area of any convex surface. 6. A crown molding. 7. The high point at the center of a road’s cross section. 8. The leafy top of a tree or shrub. 9. In plumbing, that part of a trap where the direction of flow changes from upward to downward.

crown, 9

crown course A course of curved asbestos sheet or tile, used to cap the ridge of a roof.

crown glass A handmade glass of soda-lime composition, used for windows; manufactured in the early 19th century by a now-obsolete process in which a hollow sphere of glass was blown while still very soft, then spun to form a large, nearly flat circular disk. During the spinning process, ripple lines were formed in a pattern of concentric circles, with their center at the center of the spun disk; this central area was used in a bull’s eye window. Also see glass.

crowning See crown.

crown molding Any molding serving as a corona or otherwise forming the crowning or finishing member of a structure.

crown molding

crown plate 1. Same as bolster. 2. A longitudinal structural member at the apex of a roof that supports the upper ends of the rafters.

crown post Any vertical member in a roof truss, esp. a king post.

crown rafter In a hip roof, the central common rafter.

crown saw, cylinder saw, hole saw A rotary saw used to cut round holes; has teeth along the edge of a hollow cylinder.

crown silvered lamp See CS lamp.

crown steeple A decorative termination of a tower or turret, resembling a crown.

crown tile See ridge tile.

crown under rafter Same as crown rafter.

crown vent In plumbing a vent pipe which is connected at the crown, 9 of a trap.

crown vent

crown weir On the internal surface of a trap for a plumbing fixture, the highest point of the bottom surface at the crown, 9.

crown weir

crownwork A medieval fortified structure consisting of a central bastion and two demibastions.

crow’s-foot Same as crowfoot.

crowsfooting A minor defect in paint whereby isolated unconnected wrinkles resembling a bird’s foot are formed when a paint film dries.

crowstep See corbiestep.

crowstep gable Same as corbie gable.

crowstone The top horizontal stone of a corbie gable.

cruciform 1. Cross-shaped. 2. The characteristic plan for Gothic and other large churches formed by the intersection of nave, chancel, and apse with the transepts.

cruciform

cruck One of a pair of naturally curved timbers, along the outer walls, that support the ridge beam of a timber-framed house or farm building.

cruck house A medieval house in which the roof is carried on pairs of naturally curved timbers.

crushed gravel The product resulting from the artificial crushing of gravel with substantially all fragments having at least one fractured face. Also see coarse aggregate.

crushed stone, crushed rock The product resulting from the artificial crushing of rocks, boulders, or large cobblestones, substantially all faces of which have been crushed. Also see coarse aggregate.

crusher-run aggregate Aggregate, 1 that has been broken in a mechanical crusher and has not been subjected to any subsequent screening process.

crusher-run base A base course for asphaltic or portland cement concrete paving consisting of crusher-run aggregate.

crushing strength The ultimate strength of a brittle material (such as concrete) at which disintegration by crushing occurs; the greatest compressive stress it can withstand without fracture.

crush plate 1. An expendable strip of wood which is attached to the edge of a concrete form or to the intersection of fitted forms; used to protect the form from damage during pulling, prying, or other stripping operations. 2. A wrecking strip.

crush-room (Brit.) A foyer.

crutch, cruck One of a pair of naturally curved timbers that rise from the outer walls to support the ridge beam, each crutch being called a blade, 4; joined at the top and connected by one or two tie beams, the resulting arched frame forming the unit in the framework of old English houses or farm buildings; pairs of crutches were placed at approximately equal intervals.

crutch house, cruck house A medieval English house in which the roof is carried on pairs of crutches.

crypt 1. A story in a church below or partly below ground level and under the main floor, particularly of the chancel, often containing chapels and sometimes tombs. 2. A hidden subterranean chamber or complex of chambers and passages.

crypt

cryptocrystalline A rock texture that is too fine to be discernible with an optical microscope.

cryptoporticus An enclosed gallery with walls and windows rather than columns, often partially underground for more constant temperature.

crystal glass A clear glass, made as nearly colorless as possible.

crystalline glaze A glaze containing macroscopic crystals.

crystallized finish A wrinkled paint finish caused by fast-drying vehicles containing oils which have not been gasproofed.

crystal palace 1. An exhibition building constructed in large part of iron and glass in Hyde Park, London for the great exhibition of 1851. 2. Any exhibition building similarly constructed.

CS 1. Abbr. for “caulking seam.” 2. Abbr. for cast stone.

CSA Abbr. for Canadian Standards Association.

C-section A C-shaped cross-sectional configuration; used as a structural framing member.

CSG On drawings, abbr. for casing.

CSI Abbr. for the Construction Specifications Institute.

CSI division One of the 16 divisions designated and illustrated under construction documents.

CSK On drawings, abbr. for countersink.

CS lamp An incandescent lamp, the interior of which is silvered, so that it acts as a reflector, narrowing the beam of light.

CTB On drawings, abbr. for “cement treated base.”

CTD On drawings, abbr. for “coated.”

C to C On drawings, abbr. for center-to-center.

CTR On drawings, abbr. for center.

cu Abbr. for “cubic.”

cubage The architectural volume of a building; the sum of the products of (a) the areas and (b) the height from the underside of the lowest floor construction system to the average height of the surface of the finished roof above, for the various parts of the building.

cubby 1. A small closet or storage space. 2. A diminutive room. 3. A small snug hiding space.

cube strength In a test of the strength of portland cement, the load per unit area at which a concrete cube (of standard size) fails when tested in a specified manner.

cubical aggregate Angular aggregate most of whose particles have length, breadth, and thickness approximately equal.

cubicle 1. A very small enclosed space. 2. A carrel.

cubiculum 1. In ancient Roman architecture, a bedchamber. 2. A mortuary chapel attached to a church. 3. A burial chamber having, on its walls, compartments for the reception of the dead.

cubic yard In the US, the customary unit for measuring the volume of embankments, refuse, etc.; equivalent to the volume of a cube, each edge of which measures 3 feet; equals a volume of 0.765 cubic meters.

cubic yard bank measurement (cybm) The number of cubic yards of material in its original place in the ground.

cubic yard compacted measurement (cycm) The number of cubic yards of excavated material after compaction.

cubiform capital Same as cushion capital.

cubit A linear unit of measurement used by the ancients; in ancient Egypt, equal to 20.62 in. (52.4 cm).

cu ft Abbr. for “cubic foot.”

cu in. Abbr. for “cubic inch.”

cul-de-four A half-dome or quarter-sphere vault, as over an apse or niche.

cul-de-lampe A pointed, pendant ornament used at the apex of a vault and to terminate protruding, elevated structures. Also see drop, pendant.

cul-de-lampe

cul-de-sac A street, lane, or alley closed at one end, usually having an enlarged, somewhat circular area for turning around.

culina In ancient Rome, a kitchen.

cull, brack, wrack A piece of lumber or brick of a quality below the lowest accepted grade or below specifications.

cullis See coulisse.

cult temple A temple devoted to the worship of a divinity, as distinguished from a mortuary temple.

cultured marble An artificial marble.

culver hole Same as putlog hole.

culvert A passage below ground level which permits the flow of water; often a large diameter metal or concrete pipe.

cu m Abbr. for “cubic meter.”

cumar gum A synthetic resin, used in varnishes to provide alkali-resistant properties.

Cumberland house A one-story house, primarily found in Tennessee, of the general type described under folk architecture; usually had a gable on one or both ends of the house and a front porch that often served as the center of family activity.

cumulative batching Measuring more than one ingredient of a batch of concrete in the same container by bringing the batcher scale into balance at successive total weights as each ingredient is accumulated in the container.

cuneiform Having a wedge-shaped form; esp. applied to characters, or to the inscriptions in such characters, of the ancient Mesopotamians and Persians.

cuneiform pile A pile which is tapered or step-tapered.

cunette Around a medieval fort, a dry defensive ditch in the middle of a narrow moat to improve its drainage.

cuneus 1. One of the wedge-shaped sections for spectators in an ancient theater. 2. Same as voussoir or wedge.

cuniculus A low underground passage.

cup 1. The deviation of the face of a board from a plane. 2. A metal insert in a countersunk screw hole.

cup base A device to hold a cylindrically shaped steel column in place at its base.

cupboard An enclosed storage space with shelves, esp. for dishes, glassware, etc., usually placed in kitchens or pantries.

cup escutcheon On a sliding door, a plate which has a recess to provide a fingerhold; contains a flush ring flush with the surface of the plate.

cup joint A joint between two lead pipes in a straight line; the tapered end of one is fitted into the flared end of the other.

cupola 1. A domed roof or ceiling. 2. A domed structure, often set on a circular or polygonal base on a roof or set on pillars; often glazed to provide light in the space below, or louvered to provide ventilation in that space.

cupola

cup shake A shake occurring between annual rings; a ring shake.

curb, Brit. kerb 1. A low wall of wood, metal, or masonry built around an opening in a roof or placed on the surface of a roof to support equipment. 2. A raised rim of concrete, stone, or metal which forms the edge of a street, sidewalk, or planted area. 3. A purlin plate.

curb box, curb-stop box, curb-valve box, Buffalo box A vertical sleeve which provides access to a buried curb cock; the cock is turned by a long key which is inserted through the sleeve to the cock.

curb cock, curb stop In a water-service pipe, a control valve for the water supply of a building, usually placed between the sidewalk and curb; used to shut off the water supply in case of emergency.

curb cock

curb edger See curb tool.

curb form A specially shaped form for concrete, used in conjunction with a curb tool to give the desired shape and finish to a concrete curb.

curbing 1. Material used for forming curbs. 2. Slabs and blocks of stone or concrete set on edge, straight or curved, forming an upward projection; used as a curb, 2.

curbing machine A machine that extrudes a continuous strip of asphalt or concrete through a shaped template as it moves forward.

curb joint, Brit. curb roll, knuckle joint The horizontal joint that occurs at the intersection of the two slopes of a curb roof.

curb level 1. The elevation of the street grade, 2, fixed by municipal authorities. 2. The elevation at the point of the street grade that is opposite the center of the wall nearest to, and facing, the street line. 3. The legally established level of the curb in front of a building, measured at midpoint of the line along the front.

curb line The line coincident with the face of the street curb adjacent to the roadway.

curb plate 1. The wall plate of a circular or elliptical domical roof, or of a skylight. 2. The plate which receives the upper rafters of a curb roof.

curb rafter One of the upper rafters of a curb roof.

curb ramp A short ramp cut through a curb.

curb roll 1. Same as curb joint. 2. A wood roll covered with lead at the intersection of the two sloped surfaces of a curb roof.

curb roof A pitched roof that slopes away from the ridge in two successive planes; known as a gambrel roof in the US and as a mansard roof in Britain.

curb roof

curbstone A stone forming a curb or part of a curb.

curb stop See curb cock.

curb-stop box See curb box.

curb string, curb stair string Same as close string.

curb tool, curb edger A tool used to give the desired finish and shape to the exposed surfaces of a concrete curb.

curb-valve box See curb box.

curdling The thickening of varnish in a can.

cure 1. To change the physical properties of an adhesive or sealant by chemical reaction, which may be condensation, polymerization, or vulcanization; usually accomplished by the action of heat and catalyst, alone or in combination, with or without pressure. 2. For concrete, see curing. 3. To provide conditions conducive to the hydration process of stucco or portland cement. 4. To provide a sufficient quantity of water and to maintain the proper temperature within a plaster to ensure cement hydration.

curf Same as kerf.

curia The council house in a Roman municipality.

curing Maintaining the humidity and temperature of freshly placed concrete during some definite period following placing, casting, or finishing to assure satisfactory hydration of the cementitious materials and proper hardening of the concrete.

curing agent A catalyst; a hardener.

curing blanket A built-up covering of sacks, matting, burlap, wet earth, sawdust, straw, or other suitable material placed over freshly finished concrete; such covering is moistened to supply water in the early hydration process, and tends to maintain a uniform temperature.

curing compound A liquid which is sprayed (or otherwise applied) to newly placed concrete which retards the loss of water during curing.

curing cycle 1. See autoclaving cycle. 2. See steam-curing cycle.

curing kiln See steam box.

curing membrane A sheet or layer of impervious material laid or sprayed over freshly poured concrete to restrict evaporation of mixing water so that the hydration process can be sustained. Also see membrane curing.

curing temperature The temperature to which an adhesive must be subject in order to ensure that it will cure satisfactorily; usually the time to effect a satisfactory cure (i.e., the curing time) is also specified.

curing time The length of time required to effect the cure of a plastic or resin by chemical reaction.

curl A winding, swirling, or circling in the grain of wood, usually obtained from the crotch or fork of a tree; also see fiddleback.

curling The distortion of a member, originally linear or planar, so that it is curved in shape, e.g., the warping of a slab as a result of temperature differences.

current The flow of electricity in a circuit; the unit of measurement is the ampere.

current-carrying capacity The maximum current which an electric device is rated to carry without excessive overheating and consequent premature breakdown or combustion; also see ampacity.

curstable A course of stones with moldings cut on them. May be a stringcourse of part of a cornice.

curtail A short, spiral, scroll-like termination of any architectural member, as at the end of a stair rail.

curtailment In reinforced concrete, the bending of the ends of reinforcing rods to provide added strength.

curtail plate A plate, 2 that acts as a support for a gambrel roof where the roof changes pitch.

curtail step A step, usually lowest in a flight of stairs, having one or both ends rounded in a scroll shape that projects beyond the newel. Also called a scroll step.

curtain Same as curtain wall, 2.

curtain board, draft curtain A substantial noncombustible curtain, hung tightly against a roof or ceiling along the perimeter of a special-hazard area; acts as a partition in directing heat and smoke within the curtained area toward vents and preventing the spread of fire.

curtain coating The application of paint by passing the object being coated under a continuous falling sheet of paint.

curtain drain Same as intercepting drain.

curtain grouting The injection of grouting below the surface, so as to create a mass of grout which is oriented transverse to the direction of anticipated water flow.

curtaining Gross sagging of a paint film, such that a pattern resembling the ruffles on a curtain is formed. Also see sagging, 3.

curtain line A line on a theater stage, usually imaginary, where the act curtain touches the stage floor.

curtain set The set of rigging (lines, arbor, sheaves, operating line, etc.) associated with a curtain on a theater stage.

curtain track A horizontal arrangement of continuous supports for draperies, permitting the draperies to be drawn along a track.

curtain wall 1. In a tall building of steel-frame construction, an exterior wall that is non-load-bearing, having no structural function; also see metal curtain wall. 2. In ancient fortifications, an enclosing wall or rampart connecting two bastions or towers.

curtain wall, 2

curtilage The ground adjacent to a dwelling and appertaining to it, as a yard, garden, or court.

curvature friction The friction resulting from bends or curves in the specified profile of posttensioned tendons.

curved muntin A secondary framing member (i.e., a muntin) that is curved, usually at its upper end.

curved muntins

curved pediment Same as segmental pediment.

curvilinear gable Same as multicurved gable.

curvilinear parapet A parapet whose outline usually consists of a combination of several curved and straight lines, as, for example, in a mission parapet.

Curvilinear style The later, richer period of the Decorated style of English Gothic architecture, in the second half of the 14th cent.

curvilinear tracery See flowing tracery.

cusec A unit equal to one cubic foot per second.

cushion 1. A convex element resembling a pad. 2. A corbel for roofing, a padstone. 3. Padding, as around glass, to reduce the effects of vibration and abrasion. 4. A piece of timber acting as a cushion or buffer to resist or receive the force of another part of the framing; a cushion piece.

cushion-back carpet A carpet which has a resilient, cushion-like material that is an integral part of its backing.

cushion capital 1. A capital resembling a cushion that is pressed down because of weight on it. 2. In medieval, esp. Norman, architecture, a cubic capital with its lower angles rounded off.

cushion course 1. A convex fascia. Also see torus. 2. Same as bedding course, 2.

cushioned vinyl flooring Vinyl sheet flooring which has a resilient foam layer incorporated as part of its thickness.

cushion capital, 2

cushion frieze A frieze that bulges outward at its sides, as found in the convex profile of the frieze in some Classical orders.

cushion frieze

cushion head, Brit. pile helmet A cap which covers and protects the head of a pile while it is being driven into the ground by a pile driver.

cushion head

cushioning Same as carpet underlayment.

cushion piece See cushion, 4.

cushion rafter See auxiliary rafter.

cushion sand Sand that is used as a bed onto which a concrete mix is poured.

cusp 1. The intersection of two arcs or foliations in a tracery. 2. The figure formed by the intersection of tracery arcs. Also see foil.

types of cusps

cusped arch See foil arch.

cuspidation A system of ornamentation consisting of or containing cusps, as in a multifoil arch.

custom-built Constructed on the jobsite from material which was not prefabricated, as distinguished from “factory-built.”

custom-grade lumber Normal- or middle-grade lumber, both with respect to material and quality of workmanship; intended for conventional high-quality work. Compare with economy-grade lumber and premium-grade lumber.

customhouse A building where customs duties are received.

custom millwork See architectural millwork.

cut 1. Excavated material. 2. The void resulting from the excavation of material. 3. The depth to which material is to be excavated to bring the surface to a predetermined grade. 4. In the theater, a long slot across the stage floor for the introduction or removal of scenery.

cut-and-cover A method of laying a pipe (or constructing a tunnel) by excavating a trench, then laying the pipe (or constructing the tunnel lining), and finally covering it with excavated material.

cut and fill The process of excavating, moving the excavated material to another location, and using it as fill, 1.

cut-and-fill line On a site plan, a line that joins those points that are neither cut (excavated) nor filled (by the placement of additional material).

cut and fit Same as scribed joint.

cut-and-mitered string An open string of which the vertical edges of the notches are made to miter with the ends of the risers.

cut-and-mitered valley A valley which is close-cut.

cut-and-rubbed brick A brick that is cut to size and then rubbed to produce the required finish.

cutaway drawing A pictorial representation of an object, showing its interior as if a slice of the object had been removed.

cutback asphalt An organic, bituminous roof coating or flashing cement in a volatile solvent, applied without heat; also used for dampproofing and for priming concrete and masonry surfaces.

cut bracket A bracket-shaped piece of board (for example, a bracketed string) used either for support or as a decoration.

cut brick A roughly shaped brick, cut and trimmed with a bolster.

cut glass A glass which has been decorated by grinding figures or patterns on its surface by abrasive means, followed by polishing.

cut line In a theater stage, a rope which can be cut in case of fire backstage, automatically dropping the asbestos curtain and/or opening the smoke hatches.

cut nail A nail having a wedge shape, sheared from sheet steel; has a sheared-square, blunt point.

cut nails

cutoff 1. The prescribed elevation at which the top of a drive pile is cut. 2. A structure, such as a wall, intended to eliminate or reduce percolation through porous strata.

cut-off elevation Of a pile, the elevation of the top of the pile which is indicated on the contract drawing.

cutoff sprinkler A fire sprinkler whose heads produce a curtain of water across a door when a fire alarm system is activated; prevents the spread of flames.

cutoff stop On a doorframe, a stop which terminates above the floor line and has a closed end.

cut-off wall A wall, constructed underground, designed to impede the flow of water.

cutout 1. Any opening in a masonry, metal, grating, or wood surface, as an opening in a doorframe to receive door hardware. 2. A piece of material stamped out of sheet metal or other sheet material. 3. A circuit breaker or valve for breaking an electrical or piping connection.

cutout box In electric wiring, a metal enclosure that houses circuit breakers or fuses; is designed for surface mounting, with a swinging door or cover to provide easy access.

cut pile A carpet having a pile attached to the carpet backing so that individual strands project upward by a uniform amount (see carpet pile height).

cut roof, terrace roof A pitched roof, 1, which is truncated, forming a flat roof, 1; has no ridge.

cut splay An oblique cutting of a brick to fit a slope, a splay, or the like.

cut section Same as cut, 3.

cut stone Building stone cut or machined to a specified size and shape, each piece fabricated to conform with drawings, for installation in a designated location in a finished structure.

cut string, cut stringer Same as open string.

cut size Said of an area of flat glass that has been cut from a manufactured sheet to fit in a prepared opening.

cut stock Softwood stock that has been processed at the mill so that maximum waste is left at the mill.

cutter, rubber A soft brick, sometimes used for facework because of the facility with which it can be cut or rubbed down.

cutting A short piece of lumber resulting from crosscutting or ripping operations.

cutting and waste See circular cutting and waste.

cutting gauge A tool with an adjustable stop similar to a marking gauge but with a cutting blade instead of a marking pin; used for cutting veneer and thin wood.

cutting in Careful use of a brush to paint the edge of a corner wall, ceiling area, door, or window frame.

cutting list A tabulation of the dimensions of wooden pieces or timbers required for a particular job.

cutting pliers Pliers with jaws having sharp edges esp. adapted for cutting wire.

cutting screed A tool with a sharp edge; used for trimming shotcrete to a finished outline.

cutting stock In stone milling, slabs of suitable size and thickness from which cut stone units are fabricated.

cutting torch A device used in oxygen, air, or powder cutting for controlling and directing the gases used for preheating and the oxygen or powder used for cutting the metal.

cutting waste The waste of materials that occurs as a result of the difference in size between that which is required for a construction job and that which is usually commercially available.

cut-work See gingerbread.

cu yd Abbr. for “cubic yard.”

CV Symbol for swing check valve.

CV1S Abbr. for “center vee one side.”

CV2S Abbr. for “center vee two sides.”

CW 1. On drawings, abbr. for “cold water.” 2. On drawings, abbr. for “clockwise.” 3. Abbr. for “cool white.”

C/W Abbr. for clerk of the works.

cwt Abbr. for “hundred weight.”

CWX Abbr. for “cool white deluxe.”

cybm Abbr. for cubic yard bank measurement.

cycle See alternating current.

cycles per second A unit of frequency.

cycloid A curve generated by a point in the plane of a circle when the circle is rolled along a straight line, keeping always in the same plane.

cycloidal arch An arch whose intrados forms a cycloid.

cyclone cellar A covered area below grade; a place of refuge from dangerous windstorms. Also called a storm cellar.

cyclone collector A conical sheet-metal device for separating and collecting particles from the air by centrifugal force; used in exhaust systems, esp. in factories.

Cyclopean 1. Describing prehistoric masonry, made of huge stone blocks laid without mortar. 2. Megalithic.

Cyclopean, 1 wall

cyclopean concrete Mass concrete in which large stones, each of 100 lb (45.4 kg) or more, are placed and embedded as the concrete is deposited; such a stone is called a pudding stone or plum; they are usually not less than 6 in. (15 cm) apart and not closer than 8 in. (20 cm) to any exposed surface. Also see rubble concrete.

cyclorama A curved backdrop at the rear of a theater stage, sometimes extending around to the proscenium arch in a U-shape; usually painted to simulate the sky.

cyclostyle A circular colonnade which is open at the center.

cycm Abbr. for cubic yard compacted measurement.

cylinder In a lock, the cylindrically shaped assembly containing the tumbler mechanism and the keyway, which can be actuated only by the correct keys.

cylinder collar A plate or ring used under the head of the cylinder for a lock.

cylinder glass In the past, a type of relatively poor-quality glass made by blowing a cylinder of molten glass, dividing it lengthwise, and then rolling these sheets flat while the glass was still hot; much cheaper than the higher-quality crown glass then available; also called sheet glass.

cylinder lock A door lock in which the locking mechanism is contained in a cylinder that includes the keyhole but is separated from the lock case.

cylinder saw See crown saw.

cylinder screw In a lock mechanism the setscrew that prevents the cylinder from being turned after installation.

cylinder strength Of concrete, same as compressive strength.

cylinder test A test to determine the compressive strength of concrete by subjecting a concrete test cylinder to compression.

cylinder wrench Same as pipe wrench.

cylindrical barn Same as circular barn.

cylindrical lock A bored lock which has a cylindrical case into which a separate latchbolt case fits.

cylindrical lock

cylindrical stair Same as spiral stair.

cylindrical vault A barrel vault.

CYL L On drawings, abbr. for cylinder lock.

cyma, cima A molding having a profile of double curvature; one having an ogee profile.

cyma recta, Doric cyma A molding of double curvature which is concave at the outer edge and convex at the inner edge.

cyma reversa, Lesbian cyma A molding of double curvature which is convex at the outer edge and concave at the inner edge.

cyma recta

cyma reversa

cymatium The crowning molding of a classical cornice, esp. when it has the form of a cyma, though it may also be an ovolo or cavetto; an ogee.

cymbia See cimbia.

cypress A moderately strong, hard, and heavy softwood of the US; its heartwood is naturally decay-resistant and is used for exterior and interior construction where durability is required.

cyrtostyle A projecting curved portico, usually semicircular, having columns.

cymatium