E

eachea One of a number of earthen or bronze vases described by Vitruvius as being installed under the seats of open-air theaters for “reinforcing” the voices of the actors; it is doubtful that such vases were employed.

eagle A pediment of a Greek building.

E&CB1S Abbr. for “edge and center bead one side.”

E&CV1S Abbr. for “edge and center vee one side.”

E and OE Abbr. for “errors and omissions excepted.”

ear 1. Any small projecting member or part of a piece or structure, either decorative or structural. 2. See shoulder, 1. 3. Same as crossette, 1.

eared architrave Same as crossette.

EAR lamp An incandescent lamp part of whose envelope acts as an ellipsoidal reflector; used with small-aperture downlights.

earliest event occurrence time In CPM terminology, the earliest point in time that all activities that precede the event will be completed.

Early American See American Colonial architecture.

Early Christian architecture The final phase of Roman architecture from the 4th to the 6th cent., primarily in church building. Coeval with and related to the rise of Byzantine architecture.

Early Classical Revival Occasionally, a synonym for the Classical Revival style, which was popular in America from about 1770 to 1830; the addition of the adjective Early is intended to differentiate this style from Neoclassical style, a later reuse of classical architecture between about 1895 and 1940.

Early English Colonial architecture See American Colonial architecture.

Early English style The first of the three phases of English Gothic architecture, from ca. 1180 to ca. 1280, based on Norman and French antecedents and succeeded by the Decorated style. Often characterized by lancet windows without tracery.

early finish time In CPM terminology, the first day upon which no work is to be done for an activity assuming that it started on its early start time.

Early Gothic Revival See Gothic Revival.

Early Romanesque Revival A term occasionally used for Romanesque Revival, 2.

early start time In CPM terminology, the first day of the project, upon which work on an activity can begin if every preceding activity is finished as early as possible.

early stiffening See false set.

early strength The strength of concrete or mortar developed soon after placement, usually during the first 72 hr.

Early Victorian See Victorian architecture.

earlywood See springwood.

earth 1. British term for ground, 3. 2. See soil, 1.

earth auger An auger, 2.

earth berm See berm.

earth building Same as sod house.

earth cellar A cellar that is dug into the face of steeply sloping ground, with its floor at approximately the same level as the ground at the entrance door; provides an effective place for storing food because the surrounding earth keeps the interior cool. Compare with root cellar.

earth dike Same as dike, 4.

earth drill Same as auger, 2.

earth electrode In electric wiring a metal plate, water pipe, or other type of conductor buried in the earth in a manner ensuring a good conductive path to the ground.

earthenware 1. A glazed or unglazed nonvitreous ceramic whiteware, having an absorption of more than 3%. 2. See stoneware.

earthfast Descriptive of a timber-framed structure that is supported on posts sunk in the ground, rather than supported by a foundation; also see post-in-ground construction and poteaux-enterre house.

earth floor In many types of primitive dwellings, a floor providing a reasonably durable walking surface, and that was usually composed of a compacted mixture of earth, ashes, clay (if available), with additives such as lime, pebbles, or straw. Another addition—animal blood—was once thought to improve the stability of the compacted soil. Also see rammed earth.

earthing conductor British term for grounding electrode conductor.

earthing lead British term for grounding conductor.

earth material Any rock, fill, natural soil, or combination thereof.

earth pigment, mineral pigment, natural pigment A pigment which is produced by physical processing of materials mined directly from the earth.

earth plate 1. An earth electrode in the form of a buried metal plate. 2. British term for buried plate electrode.

earth pressure 1. The horizontal thrust which is exerted by retained earth. 2. The pressure exerted on a structure, such as a wall, by the earth which it retains.

earthquake load The total force exerted on a structure by an earthquake.

earth roof See sod roof.

earth-sheltered construction A building in which at least 50% of the combined area of the walls and roof are covered with a thick layer of earth.

earth table Same as ground table.

earth-wall dwelling See jacal, pueblo architecture, sod house.

earthwork 1. Operations connected with the movement of earth. 2. A construction made of soil.

ease A curve at the lower end of a handrail, where it meets the newel post that supports the handrail.

eased Said of a building component, any edge of which is slightly rounded, for example, as a stair nosing.

eased edge Any edge which is rounded slightly.

easement 1. A right of accommodation (for a specific purpose) in land owned by another, such as right-of-way or free access to light and air. 2. A curve formed at the juncture of two members; forms a smooth transition between surfaces that would otherwise intersect at an angle. 3. Those portions of stair handrails which are curved in the vertical plane only; an “easement curve.”

easing 1. Removal of material to enable a piece to be fitted into an allotted space. 2. See basement, 2.

east end The end of a church where the principal altar is placed; so called because medieval churches almost invariably had their sanctuaries at the east end and the main doors at the west end.

Eastern closet Same as Asiatic water closet.

eastern crown See antique crown.

eastern hemlock, hemlock spruce, spruce pine Wood of a coniferous tree of eastern North America; moisture-resistant, soft, coarse, uneven-textured; splinters easily; inferior for use in construction.

Eastern method See pick and dip.

eastern red cedar, aromatic cedar A highly aromatic, moderately high-density, fine-textured wood of a distinctive red color with white streaks; widely used for fence posts, shingles, and mothproof closet linings.

Eastern Stick style Same as Stick style; also see Western Stick style.

eastern water closet Same as Asiatic water closet.

Easter sepulcher In some churches, in which sacred elements are placed from Maundy Thursday to Easter, an embrasure on the left wall of the chancel.

East Indian laurel A dense, moderately hard wood; light to dark brown in color, with dark streaks; found in India and Burma. Used for cabinets, paneling, and interior finish; resembles black walnut.

East Indian rosewood A hard, dense wood; purplish in color, with black streaks; used for decorative paneling and cabinets.

Eastlake ornamentation, Eastlake style A style not of architecture but of ornamentation, associated with the English designer Charles Locke Eastlake (1836–1906). Decorative elements included: spindlework (especially balusters or posts turned on a lathe), perforated bargeboards and pediments, carved panels, large ornamental fanlike brackets, highly ornamental moldings, and decorative hardware fittings such as door knobs and locks.

east window In church architecture, a window at the choir end of the church, which is commonly the east end.

eave lead A lead gutter, 1.

eaves That part of a roof that projects beyond the exterior wall; usually the lower edge of a sloped roof. Also see bellcast eaves, boxed eaves, bracketed eaves, closed eaves, coved eaves, flared eaves, open eaves.

eaves board Same as eaves fascia.

eaves bracket A bracket that supports the eaves of a roof; usually one of many, often in pairs.

eaves channel A channel or small gutter along the top of a wall; conveys the roof drippings to spouts or gargoyles.

eaves cornice A cornice at the eaves of a roof.

eaves course 1. The first course of slates, shingles, or tiles at the eaves on a roof. 2. Same as double course.

eaves fascia A board that is nailed vertically at the ends of roof rafters; sometimes supports a gutter; also called a fascia board.

eaves flashing A metal strip which is dressed into an eaves gutter, acting as flashing.

eaves gutter See gutter, 1.

eaves lath A strip of wood beneath the lowest course of shingles on a roof (i.e., at the eaves) that raises the lower edges of the shingles so they are nailed at the same slope as the shingles above them.

eaves plate A horizontal wood beam, at the eaves, which is supported at its ends by piers or posts; carries the lower ends of roof rafters.

eaves pole A cant strip.

eaves soffit The horizontal surface under projecting eaves.

eaves tile, starter tile Tile, usually shorter or plainer than the other roofing tile, used in the first course of tile along the eaves of a building.

eaves trough See gutter, 1.

EB1S Abbr. for “edge bead one side.”

ebonize To blacken with paint or stain to look like ebony.

ebony Wood of a number of tropical species usually distinguished by its dark color, durability, and hardness; used for carving, ornamental cabinetwork, etc.

eccentric Not having the same center or center line.

eccentric-braced frame A frame whose centerline braces are offset from the intersection of the centerlines of the columns and beams.

eccentric fitting Any fitting, 1 in which the center line is offset from that of the run of pipe.

eccentric load A load on a column or pile which is nonsymmetric with respect to the central axis, therefore producing a bending moment.

eccentric tendon In prestressed concrete, a tendon which follows a trajectory not coincident with the gravity axis of the member.

ecclesiology The study of the furnishing and adornment of churches.

échauguette A bartizan.

echinus The convex projecting molding of eccentric curve supporting the abacus of the Doric capital. Hence the corresponding feature in capitals of other orders, which often had egg-and-dart ornamentation; any molding of similar profile or decoration. Also see ovolo, bowtell.

echinus and astragal An ornament similar to egg and dart with a bead and reel below it.

echo Sound waves which have been reflected to a listener with sufficient magnitude and time delay so as to be perceived separately from those communicated directly to the listener.

eclectic architecture Architecture that combines elements and characteristics of a wide range of historic styles. See Exotic Eclectic architecture, French Eclectic architecture, Neo-Eclectic architecture, Spanish Eclectic architecture.

Eclecticism The selection of elements from diverse styles for architectural decorative designs, particularly during the second half of the 19th cent. in Europe and the US.

École des Beaux-Arts The school in Paris that taught elaborate, historic, and eclectic architecture, designed on a monumental scale, based on classical architecture of Hellenic Greece and Imperial Rome, that adapted features of French architecture of the 16th, 17th, and 18th centuries; became a State institution in 1863 and still is the center of the teaching of architecture in France. Also see Beaux-Arts style.

economic rent That rent on a property which is sufficient to pay all costs of operation, maintenance, and payment of mortgages (but not utilities and services).

economy brick A cored, modular brick whose nominal dimensions are 4 in. by 4 in. by 8 in. (10.16 cm by 10.16 cm by 20.36 cm); actually about 3½ in. by 3½ in. by 7½ in. (8.89 cm by 8.89 cm by 19.05 cm).

economy-grade lumber The lowest grade of lumber; intended for work where price is the primary consideration. Compare with custom-grade lumber and premium-grade lumber.

economy wall A brick wall, 4 in. (10 cm) thick, back-mortared and strengthened at intervals by vertical pilasters to support floor or roof framing.

ecphora The projection of any member or molding beyond the face of the member or molding directly below it.

ectype A copy or image in relief or embossed.

eddy flow See turbulent flow.

edge-bar reinforcement In concrete construction, tension steel used as reinforcement to strengthen insufficiently strong edges of a concrete slab.

edge bead See corner bead.

edge beam A stiffening beam at the edge of a slab.

edge-bedded See face-bedded.

edgebend British term for crook, 1.

edge clearance The distance between the edge of a pane of glass or a panel and its surrounding frame, measured in the plane of the pane or panel.

edge isolation Same as expansion strip.

edged tool See edge tool.

edge form A form to limit the horizontal spread of the freshly poured concrete on a flat surface or slab.

edge-glued core See continuous block core.

edge-grained, comb-grained, quartersawn, rift-grained, vertical-grained Descriptive of wood sawn so that the annual rings intersect the wide face at an angle of 45° or more.

edge joint 1. A joint formed between two veneers or laminations, in the direction of the grain. 2. A joint formed between two boards or plates which are side-by-side.

edge molding, edging, edge strip Any molding on the edge of a door, counter, or other relatively thin member.

edge nailing, edge toenailing Nailing through the edges of boards, such as flooring, so that each board conceals the nailing in the adjacent one.

edge plate On a door, an angle iron or a channel-shaped guard used to protect the edge of a door.

edge pull A pull which is mortised into the edge of a sliding door.

edger 1. A finishing tool used on the edges of fresh concrete or plaster to provide a rounded corner. 2. A wood sanding machine for use along the edges of wood floors.

edge roll See bowtell.

edge set Descriptive of brick which is laid on its narrow side rather than its flat side.

edge shafts Shafts which sustain arches, united by their sides and back to the nearest wall or arch, so they appear to support their edge only; abundantly used in Norman architecture.

edge-shot Planed on the edges, as a board.

edge spacer In window construction, a spacer which (a) prevents edge contact and (b) positions laterally a pane of glass or panel within a supporting frame.

edgestone A stone used for curbing.

edge toenailing See edge nailing.

edge tool, edged tool Any tool having a sharp cutting edge, such as a plane or chisel.

edge tracking In painting with a roller, the trails that may result from either or both ends of the paint roller.

edge vent One of the openings at the perimeter of a roof to relieve possible water-vapor pressure in the roof system.

edging 1. Edge molding. 2. A plain or molded strip of metal, wood, or other material used to protect edges of a panel or hide the laminations as in plywood or roof sheathing; an edging strip. 3. In concrete finishing, the process of rounding the exposed edges of slabs to reduce the possibility of chipping or spalling.

edging strip Same as edging, 2.

edging trowel Same as edger, 1.

edicule An aedicula.

edifice A large and important building.

Edison-base fuse A fuse rated up to 30 amperes, contained in a small glass or ceramic container that screws into a socket; has a window for observing whether the fuse has “blown.”

Edison screw A threaded metal base for an incandescent lamp.

EDR Abbr. for “equivalent direct radiation.”

educational occupancy The use of a building or buildings for the gathering of groups of six or more persons for purposes of instruction, including schools, universities, colleges, academies, nursery schools, and kindergartens.

EE 1. Abbr. for “eased edges.” 2. Symbol for “45° elbow.”

eelgrass An organic material composed of a dried grass-like sea plant; fabricated as a blanket, usually enclosed by kraft paper; the resulting enclosed air spaces provide resistance to heat flow; has been used as a thermal insulator.

effective area The net area of an air outlet or air inlet through which air can pass; it is equal to the free area of the device times the coefficient of discharge.

effective area of reinforcement In reinforced concrete, the product of the right cross-sectional area of the steel reinforcement by the cosine of the angle between its direction and the direction for which its effectiveness is considered.

effective bond A bond in brickwork which is completed at the ends with a 2½-in. (5-cm) closer.

effective depth Of a beam or slab section, the depth measured from the compression face to the centroid of the tensile reinforcement.

effective flange width The depth of a beam or section of a slab.

effective length Of a column, the distance between inflection points in the column when it bends.

effective opening The minimum cross-sectional area of the opening at the point of water-supply discharge, expressed in terms of diameter of a circle; if the opening is not circular, the diameter of a circle of equivalent cross-sectional area is given.

effective prestress The stress remaining in concrete due to prestressing after loss of prestress; includes the effect of the weight of the member, but excludes the effect of any superimposed load.

effective reinforcement That reinforcement which is assumed to be active in resisting applied stresses.

effective span The distance (measured from center to center) between supports for a beam, or the like.

effective stress In prestressed concrete, the stress remaining in the tendons after loss of prestress has occurred.

effective temperature An index which combines into a single figure the effects of temperature, humidity, and air movement on the sensation of warmth or cold felt by the human body; numerically equal to the temperature of still, saturated air which induces an identical sensation.

efficacy See luminous efficacy.

efficiency apartment A small apartment usually consisting of a single room used both as a living room and as a bedroom, together with a kitchen alcove and a bathroom.

efficiency ratio The ratio of the net usable area of a building to its gross floor area.

effigy A representation or imitation of a person, in whole or in part, as a likeness in sculpture.

efflorescence An encrustation of soluble salts, commonly white, deposited on the surface of stone, brick, plaster, or mortar; usually caused by free alkalies leached from mortar or adjacent concrete as moisture moves through it.

effluent In sanitary engineering, a liquid which is discharged as waste, esp. the discharge from a septic tank.

EG Abbr. for “edge (vertical) grain.”

e.g. Abbr. for the Latin term “exempli gratia,” which means for example.

egg and dart, echinus, egg and anchor, egg and arrow, egg and tongue An egg-shaped ornament alternating with a dart-like ornament, used to enrich ovolo and echinus moldings and also on bands. In the egg-and-anchor, egg-and-arrow, and egg-and-tongue moldings, the dart-like ornament is varied in form.

egg-and-tongue molding Same as tongue-and-egg molding.

eggcrate diffuser A metal or plastic assembly, resembling an eggcrate, used below a lighting fixture to diffuse the light it provides.

eggcrate louver A louver having rectangular openings resembling the dividers used in egg containers.

eggshell, eggshelling A semimatte glaze or porcelain enamel surface resembling eggshell in texture; sometimes a defect.

eggshell gloss Low gloss of a paint film; slightly higher in gloss than a flat or matte finish but lower than a semigloss.

eggshelling See chip cracks.

egress An exit, or means of exiting. Also see means of egress.

Egyptian architecture The architecture of Egypt from the 3rd millennium B.C. to the Roman period. Its most outstanding achievements are its massive funerary monuments and temples built of stone for permanence, featuring only post-and-lintel construction and corbel vaults without arches and vaulting.

Egyptian door A door whose frame is narrower at the top than at the bottom, with doorjambs that are inclined inward at their tops with respect to the vertical.

Egyptian gorge, cavetto cornice The characteristic cornice of most Egyptian buildings, consisting of a large cavetto decorated with vertical leaves, and a roll molding below.

Egyptian Revival A mode of Exotic Revival architecture suggestive of the architecture of ancient Egypt; used primarily from about 1800 to 1850 and then again, though rarely, from about 1920 to 1930. Buildings in this style usually include some of the following characteristics and/or decorative elements: ashlar-finished exterior walls that are tilted inward at their tops with respect to the vertical; window frames that are narrower at the top than at the bottom; Egyptian doors; lotus capitals; columns that bulge or that imitate papyrus stalks bundled by bands at the top and bottom of the columns; an Egyptian gorge; winged sun disks; an entrance portal flanked by a monumental gateway having slanting sidewalls.

EIC Abbr. for “Engineering Institute of Canada.”

EIFS Abbr. for exterior insulation and finishing system.

EIS Abbr. for “environmental impact statement.”

ejector, ejector pump 1. A type of pump for ejecting liquid, as from a sump; induces fluid flow by entraining the liquid in the flow of a stream of air, steam, or water. 2. A cleanout, 1.

ejector basin A receiving basin that collects sanitary waste discharge.

ejector grille (Brit.) 1. A ventilating grille with slots shaped to force the air out in divergent streams. 2. A British term for an air diffuser.

ejector vent A vent pipe used to convey air to a receiving basin that collects sanitary waste discharge.

EL On drawings, abbr. for elevation.

elaeothesium Same as alipterion.

elastic Descriptive of a material having the property of elasticity.

elastic arch An arch designed on the basis of the elastic theory of materials.

elastic constant 1. See modulus of elasticity. 2. See Poisson’s ratio.

elastic deflection The deflection of a structural element when a load is applied to it, and which recovers when the load is removed, as opposed to the deflection resulting from creep, 1.

elastic deformation A change in shape without impairment of the elastic properties of a material.

elastic design A method of analysis in which the design of a structural member is based on a linear stress-strain relationship, assuming that the working stresses are only a fraction of the elastic limit of the material.

elasticity The property of a body that causes it to tend to return to its original shape after deformation (as stretching, compression, or torsion).

elastic limit The greatest stress which a material is capable of sustaining without permanent deformation upon complete release of the stress.

elastic loss In pretensioned concrete, the reduction in prestressing load resulting from the elastic shortening of the member.

elastic modulus Same as modulus of elasticity.

elastic shortening 1. In a structural member, a decrease in the length (under an imposed load) which is linearly proportional to the load. 2. In prestressed concrete, the shortening of a member which occurs immediately on application of forces induced by prestressing.

elastomer A macromolecular material (such as rubber or a synthetic material having similar properties) that returns rapidly to approximately the initial dimensions and shape after substantial deformation by a weak stress and release of the stress.

elastomeric Said of any material having the properties of an elastomer, as a roofing material which can expand and contract without rupture.

elastomeric bearing An expansion bearing fabricated of an elastomer, which permits movement of the structure it supports.

elbow 1. A pipe, sheet metal, or conduit fitting having a bend, usually 90°; a 90° elbow is also called an ell. 2. A crossette, 1. 3. A shoulder, 1.

elbow-action tap A faucet having a water outlet valve whose flow is controlled by the pressure of an arm or elbow.

elbowboard 1. An elbow rail. 2. Same as window stool.

elbow catch A spring-loaded locking device commonly used to lock the inactive leaf of a pair of cabinet doors. When the inactive leaf closes, a hook on one end of the catch automatically engages a strike, thereby securing the door.

elbow rail A strip of millwork fixed to a partition as an armrest; also called an elbowboard.

elec, ELEC Abbr. for electric or electrical.

electric box Same as box, 2.

electric, electrical The qualifying adjectives electric and electrical have the following meanings: containing, producing, arising from, actuated by, or related to electricity. In general, electric is used when the term being qualified designates something that has the properties, dimensions, or physical characteristics associated with electricity; electrical is used when the term being qualified does not explicitly designate something that has the properties, dimensions, or physical characteristics of electricity (e.g., electrical engineering). However, sometimes these two terms are used interchangeably.

electric filament lamp Same as incandescent lamp.

electric riser Same as riser, 5.

electric strike plate A remote-controlled strike plate.

electrical codes See National Electrical Code (NEC) and National Electrical Safety Code (NESC).

electrical conductivity A measure of the ability of a material to conduct electric current.

electrical conduit Same as conduit, 1.

electrical curing The curing of concrete by the use of electrical heaters.

electrical distribution cutout See distribution cutout.

electrical fault See fault.

electrical insulation, insulating material A material that is a very poor conductor of electricity.

electrical insulator A component or device made from material having great enough resistance to the flow of electric current to be effectively considered as a nonconductor of current.

electrically supervised Descriptive of an electric wiring system which utilizes the flow of a small current in the circuit (too small to actuate the apparatus being supplied) to energize an alarm signal upon failure of any device or equipment in the circuit.

electrical metallic conduit (EMC) Conduit, usually fabricated of steel, which encloses electrical wiring, thereby protecting the wiring from outside damage. The difference between electrical metallic conduit and electrical metallic tubing (EMT) is that conduit is heavy-walled and usually has threaded ends; in contrast, tubing is thinner and is not threaded. Between these two is an intermediate metallic conduit (IMC), which is 25 percent lighter and less costly than EMT; it may be threaded or threadless.

electrical metallic tubing A thin-walled metal raceway having a circular cross section; used to pull in or withdraw electric cables or wires after the tubing is installed in place; uses connectors and couplings other than the threaded type.

electrical nonmetallic tubing (ENT) A round, corrugated plastic tube that is concealed in concrete, or it may be concealed in a ceiling construction having a fire rating of at least 15 minutes, provided the ceiling is not used as a plenum for return air.

electrical porcelain Vitrified whiteware having an electrical insulating function.

electrical resistance The physical property of a device, conductor, element, branch, or system, by virtue of which power is lost as heat when current flows through it; the physical property which an electric conductor exhibits to the flow of current; measured in ohms.

electrical resistivity, specific resistance The resistance, in ohms, of an electric conductor of unit cross-sectional area and unit length.

electrical rod Obsolete term for lightning rod.

electrical service connection See service connection.

electrical tape See friction tape, thermoplastic insulating tape, thermoplastic protective tape.

electric appliance See appliance.

electric-arc welding See arc welding.

electric blasting cap A blasting cap designed for and capable of detonation by means of an electric current.

electric cable See cable, 1 and cable, 2.

electric cord One or more flexible insulated electric conductors in a flexible insulating covering which is equipped with terminals.

electric-delay blasting cap A cap designed to detonate at a predetermined time after electrical energy is applied to the ignition system.

electric device See device.

electric-discharge lamp A lamp which produces light when electric current flows through a vapor or a gas; may be designated by the gas filling which is responsible for the major part of the radiation (e.g., mercury lamp, neon lamp, etc.), by the physical dimensions or operating parameters (e.g., short-arc lamp, high-pressure lamp, etc.), or by its application (e.g., black-light lamp, bactericidal lamp, etc.).

electric drill A hand-held electrically powered drill, 1; usually classified according to the capacity of the chuck; may be of either fixed or variable speed.

electric eye See photoelectric cell.

electric heating element A unit consisting of an electrical resistance material, insulated supports, and terminals for connection to a source of electric power; used as a heat source.

electricity meter A device which measures and registers the integral of an electric quantity with respect to time, e.g., a watt-hour meter.

electric lock A locking device in which the movement of a bolt or latch is actuated by the application of a voltage to the terminals of the device.

electric motor control See motor controller.

electric operator An electrically powered mechanism used to open or close a casement window, hatch, damper, or the like.

electric outlet See outlet.

electric panel heating See panel heating.

electric precipitator Same as electrostatic precipitator.

electric receptacle See receptacle.

electric resistance welding See resistance welding.

electric sign A fixed or portable self-contained, electrically illuminated appliance with words or symbols designed to convey information or attract attention.

electric space heater A space heater in which electricity supplies the heat energy.

electric squib An electrically actuated device used to ignite a charge in blasting operations.

electric stairway Same as escalator.

electric strike An electrical device that permits the release of a door at a remote location.

electric water heater A water heater, usually fully automatic, having a storage tank with one or more electric heating elements, and with operating and safety controls.

electric welding 1. See arc welding. 2. See resistance welding.

electroacoustics The science of transforming acoustical energy into electric energy and vice versa, e.g., by means of microphones or loudspeakers.

electrochemical corrosion Same as galvanic corrosion.

electrocopper glazing See copperlight glazing.

electrode 1. In arc welding, the component in a welding circuit through which an electric current is conducted between the electrode holder and the arc. 2. In resistance welding, the component through which the electric current in the welding machine passes (usually accompanied by pressure) directly to the work.

electrode hot-water heater A domestic hot-water heater that is heated by an electric current flowing through enclosed electrodes submerged in the water tank. Also see instantaneous-type water heater.

electrogalvanizing Galvanizing by a process in which the zinc is deposited by an electroplating method.

electrogas welding A method of gas metal-arc welding or flux-cored arc welding in which an external gas is supplied; for welding in a vertical position, the molding weld is confined by “welding shoes.”

electrolier A support for an electrically operated luminaire, esp. one that hangs, as a chandelier.

electroluminescence The emission of light from a phosphor excited by electromagnetic energy.

electroluminescent lamp A lamp in the form of a thin sheet, either rigid or flexible, which generates light by electroluminescence; characterized by low luminance and efficacy.

electrolysis The decomposition of a chemical compound into its constituent parts by the passage of an electric current; this action leads to the decomposition of metals.

electrolytic copper Copper that has been refined by electrolytic deposition; used for manufacture of tough pitch copper and copper alloys.

electrolytic corrosion Same as galvanic corrosion.

electrolytic protection See cathodic protection.

electromagnetic contactors Electrically actuated devices to open and close electric power circuits.

electromagnetic interference In the transmission or reception of communication signals, the interference caused by the radiation of electromagnetic fields.

electromotive force The force which causes (or tends to cause) the movement of electricity in a conductor; the difference in potential between the terminals of an electric source.

electroplated Said of a metal surface having a thin electrochemical deposit of a metal such as brass, zinc, copper, cadmium, tin, or nickel; the metal deposit usually is the result of its immersion in an electrolytic bath.

electroslag welding A welding process in which the two surfaces to be welded are fused together by use of an electrically liquefied molten slag which melts both the filler metal and the two surfaces.

electrostatic air cleaner Same as electrostatic precipitator.

electrostatic filter An electrostatic precipitator.

electrostatic paint-sprayer An electrically operated paint spray-gun in which an electric potential difference is established between the atomized paint particles and the item being sprayed. As a result, the paint particles are attracted to the item being sprayed, thereby providing a clean paint job.

electrostatic precipitator A device installed in flues, and the like, to prevent smoke and dust particles from escaping to the atmosphere; the particles are given an electric charge as they pass through a charged screen; then they are attracted to one of two electrically charged plates through which they pass; from time to time they are removed from the plates.

electro-zinc plated See galvanized.

electrum A natural alloy of gold and silver, sometimes employed in the decorations of ancient temples and palaces.

element See building element.

elementary school, grade school An educational institution which offers instruction usually from the first year through the sixth or eighth year of schooling.

elemi A fragrant yellow-brown resin obtained from tropical trees; used in varnishes and lacquers.

elephant trunk A long cylindrical tube with a hopper-like top; used as a chute for concrete in placing the concrete in deep shafts or forms; the tube is kept filled with concrete, so that there is no free fall of material and resultant segregation of its constituents is avoided.

elevated floor See raised floor.

elevated water tank A gravity water tank.

elevated-water-tank system See gravity water system. A water supply system for a building in which water is pumped from the water main to an elevated water storage tank located above the highest and most hydraulically remote point in the water supply system; the height of the tank increases the pressure in the water distribution system.

elevation 1. A drawing showing the vertical elements of a building, either exterior or interior, as a direct projection to a vertical plane. 2. The vertical distance above or below some established reference level.

elevator A hoisting and lowering mechanism equipped with a car or platform which moves in guides in a vertical direction, and which serves two or more floors of a building or structure; also see dumbwaiter. Also see freight elevator, hand elevator, hydraulic elevator, passenger elevator, power elevator, sidewalk elevator.

elevator buffer See buffer, 2.

elevator bumper See bumper, 1.

elevator car The load-carrying unit of an elevator, including its platform, car frame, enclosure, and door or gate.

elevator car annunciator An electrical device that indicates the elevator landings where call buttons have been pressed.

elevator car door A door at the entrance to an elevator car.

elevator car-frame sling The supporting frame of an elevator to which are attached the car platform, guide shoes, elevator car safety, hoisting ropes (or sheaves), and/or associated equipment.

elevator car-leveling device Any mechanism or control that, when activated, will move the car to a landing and stop the car at such landing.

elevator car platform The structure which forms the floor of an elevator car and directly supports the load.

elevator car safety, counterweight safety A mechanical device attached to an elevator car frame or to the frame of the counterweight; slows down, stops, and holds the car or counterweight in the event of excessive speed or free fall of the car, or if the wire ropes slacken, break, or pull out of their fastenings.

elevator counterweight A counterweight carried by an elevator cable to balance the weight of an elevator cab; the counterweight travels upward when the cab travels downward, and vice versa; usually composed of steel plates stacked within a frame.

elevator hoistway See hoistway.

elevator interlock A device on each door at an elevator landing; prevents movement of an elevator unless the door is locked in the closed position.

elevator landing That portion of a floor, balcony, or platform adjacent to an elevator hoist-way which is used to receive and discharge passengers or freight.

elevator machine beam, elevator sheave beam A steel beam, within an elevator machinery room, which is beneath and supports elevator equipment; usually directly over the elevator hoistway (shaft).

elevator pit That portion of an elevator shaft or hoistway extending below the level of the bottom landing saddle to provide for bottom overtravel and clearance, and for elevator parts that require space below the bottom limit of car travel.

elevator shaft An elevator hoistway.

elevator sheave beam See elevator machine beam.

elevator stage, drop stage, lift stage A theater stage floor which moves vertically on an elevator, usually so that one set can quickly replace another; may consist of a single unit or articulated sections.

elevator vestibule An elevator car enclosed by noncombustible smoke-barrier partitions that conform to applicable code requirements.

Elizabethan architecture The transitional style between Gothic and Renaissance in England, named after Elizabeth I (1558–1603); mainly country houses, characterized by large mullioned windows and strapwork ornamentation.

Elizabethan Manor style See Tudor Revival.

ell, el 1. A secondary wing or extension of a building at right angles to its principal dimension. 2. Same as elbow.

elliptical arch An arch having the shape of half an ellipse; in its construction, the ellipse is often approximated by three adjoining circular arcs.

elliptical fanlight A fanlight that has the shape of half an ellipse, often placed over a door; rods or bars radiating from a point are suggestive of the shape of an open fan. Also called a semi-elliptical fanlight.

elliptical stair A stair which winds about a solid elliptic newel or elliptically shaped well, 1.

elm A tough, strong, moderately high-density hardwood of brown color; often has twisted, interlocked grain. Common in cultivation for shade and ornament; used for decorative veneer, piles, and planks.

elongated piece A particle of aggregate having the ratio of its length to width greater than a specified value.

elongation See strain.

eluriation The conditioning of sludge from sanitary waste so that certain constituents are removed by successive decontaminations using fresh water or plant effuents, thereby reducing requirements for conditioning chemicals.

EM Abbr. for “end matched.”

emarginated Having the margin broken by a notch or notches.

embankment A bank of earth, gravel, or other material constructed above the natural ground surface; often used to carry a road, or as a dam to hold back water.

embarrado In Spanish Colonial architecture and derivatives, said of a surface that is roughly plastered with adobe or mud.

embattled, embattlemented Having battlements.

embattled molding A crenelated molding.

embattlement Same as battlement.

embedded column A column that is partly built within the face of a wall.

embedded reinforcement See reinforcement, 1.

embedding compound Same as taping compound.

embedment A steel component which is cast in concrete and used to transmit externally applied loads to the concrete structure.

embedment drawings Drawings showing the location and placement of those components that are installed to receive structural steel.

embedment length The length of embedded steel reinforcement, 1 provided beyond a critical section.

embellishment Ornamentation; adornment with decorative elements.

emblemata, emblema A type of inlaid work used by the early Romans to embellish floors, panels, and the like.

emboss To raise or indent a pattern on the surface of a material; sometimes produced by the use of patterned rollers.

embow To form in a vault or arch.

embowed Having an outward-curving projection, as a bay window.

embrasure 1. The crenels or intervals between the merlons of a battlement. 2. An enlargement of a door or window opening, at the inside face of the wall, by means of splayed sides.

EMC See electric metallic conduit.

emergency-exit lighting A system designed and maintained to assure necessary exit illumination in the event of failure of the normal lighting in the building.

emergency-exit window See fire-escape window.

emergency lighting Lighting designed to supply illumination which is essential to safety in the event of failure of the normal electric power supply.

emergency power generator See standby power generator.

emergency release On a door, a safety device other than a panic exit device which permits egress under emergency conditions.

emery A granular form of impure carborundum; used for grinding and polishing glass, stone, and metal surfaces.

emery cloth A cloth which is coated with powdered emery; used wet or dry (usually on metal) in a manner similar to that of sandpaper, esp. for fine smoothing or polishing.

emf Abbr. for electromotive force.

eminent domain The power of the state to appropriate private property, usually for public use and with the payment of compensation to the owner.

eminently hydraulic lime A hydraulic lime that sets exceedingly fast, usually in less than one week.

emission The radiation of energy (for example, electromagnetic, heat, light, or sound).

emissivity See thermal emissivity.

emittance The ratio of radiant flux emitted by a material to that emitted by a blackbody at the same temperature, under the same conditions.

Empire style The elaborate neoclassic style of the French First Empire (1804–1815).

emplecton A type of masonry commonly used by the Romans and Greeks, esp. in fortification walls, in which the exterior faces of the wall were built of ashlar in alternate headers and stretchers, and with the intervening space filled with rubble.

employer’s liability insurance Insurance protection for the employer against claims by employees for damages which arise out of injuries or diseases sustained in the course of their work and which are based on common law negligence rather than on liability under workmen’s compensation acts.

emporium In ancient Roman towns, a large building in which foreign merchandise, imported by sea, was deposited until disposed of to retail dealers.

empty-cell process A method of impregnating wood with fluid preservatives under pressure.

EMT Abbr. for electrical metallic tubing.

emulsified asphalt An emulsion of asphalt cement and water containing small amounts of an emulsifying agent.

emulsifier A substance which modifies the surface tension of colloidal droplets, keeping them from coalescing and keeping them suspended.

emulsion 1. A mixture of liquids insoluble in one another, in which one is suspended in the other in the form of minute globules. 2. A mixture in which solid particles are suspended in a liquid in which they are insoluble, as a mixture of bitumen and water, with uniform dispersion of the bitumen globules. The cementing action needed in roofing and waterproofing takes place as the water evaporates.

emulsion glue A glue, usually cold-setting, made from emulsified synthetic polymers.

emulsion paint A paint composed of small beads of resin binder which are dispersed, along with pigments, in water. On evaporation of the water, the resin particles coalesce to form a film which adheres to the surface and binds the pigment particles.

emulsion sealant See latex sealant.

ENAM On drawings, abbr. for enamel.

enamel A paint made of finely ground pigments and a resin binder that dries to form a hard, smooth, glassy film having very little surface texture.

enameled brick See glazed brick.

encarpus A sculptured festoon of fruit and flowers.

encased Said of a steel-framed structure in which all of the individual framing members are completely enclosed in cast-in-place concrete.

encased beam A metal beam enclosed in another material, usually concrete.

encased electrode An electrode encased in concrete (located within and near the bottom of a concrete footing or foundation); the electrode, which may consist of reinforcing bars or rods, must be in electrical contact with the earth.

encased knot A knot that is not intergrown with the surrounding wood; a dead knot.

encasement 1. A rigid structure or pipe which surrounds a buried pipe, providing it with added support or protection. 2. See pile encasement.

encastré Embedded.

encaustic 1. Painted with a mixture of a paint solution and wax which, after application, is set by heat. 2. Colors which have been applied to brick, glass, porcelain, and tile and set by the application of heat.

encaustic tile A tile for pavement and wall decoration, in which the pattern is inlaid or incrusted in clay of one color in a ground of clay of another color.

enceinte An enclosing wall; usually the principal perimeter of a medieval fort.

enchased Descriptive of a variety of hammered metalwork in which a pattern in relief is produced by hammering down the background or depressed portions of the design.

enclosed fuse A cartridge fuse.

enclosed knot An unexposed knot completely covered by surrounding wood so that it does not appear on the surface.

enclosed platform The partially enclosed, raised portion of an assembly room, the ceiling of which is not more than a specified distance above the top of the proscenium opening; designed or used for the presentation of plays or other entertainment wherein scenery, drops, decorations, etc., may be used.

enclosed shaft Same as covered shaft.

enclosed stair Same as box stair.

enclosure wall 1. Any non-load-bearing wall in skeleton construction; usually anchored to piers, columns, or floors; a curtain wall. 2. The curved metal or glass partition surrounding a revolving door.

encorbelment The projection of each course, 1 of masonry over the course below it.

encroachment The unauthorized extension of a building, or part thereof, on the land of another.

encumbrance A restriction on the use of real property, or an obligation to make a payment which is secured by real property and which does not prevent its conveyance.

end anchorage A mechanical device used to transmit prestressing force to the reinforced concrete in a posttensioned member.

endbeam See beam.

end-bearing pile A pile principally supported at its toe (point), which rests on or is embedded in a bearing stratum.

end-bearing sleeve A device which fits over the abutting ends of two steel reinforcing bars; used to assure transfer of axial compression only from one bar to the other.

end-bedded Same as face-bedded.

end block 1. An enlarged end section of a member, designed to reduce anchorage stresses to allowable values. 2. Same as anchor block.

endboard A wood board that closes off the end of a cornice where there is no cornice return.

end butt joint Same as end joint.

end channel A horizontal stiffener which is welded into the top and bottom of hollow-metal doors to provide strength and rigidity.

end checks Checks that develop in the end grain of lumber during drying.

end chimney A chimney located at an end gable of a house; may be either an interior chimney in which the outer surface is flush with an exterior wall, or an exterior chimney in which the chimney projects from the exterior of the end wall.

end-construction tile Tile designed to receive its principal stress parallel to the axes of the cells; laid with axes of the cells in the vertical direction.

end dam A flashing that is placed so that water cannot run out at one end.

en délit Descriptive of a Gothic stone shaft whose grain is vertical instead of horizontal.

end distance The distance between the end of a timber which is bolted and the center of the nearest bolt hole.

end gable A gable at the end wall of a house.

end girt A heavy timber that acts as a main horizontal support for the second floor in an early timber-framed house; it is located along one end of the house, for example, between a center post and each of the corner posts; serves to tie together various components of the timber framing. Also see illustration under timber-framed house.

end grain The wood grain that is exposed when a cut is made at right angles to the grain.

end-grain core Plywood or panel core composed of wood blocks sawn and glued so that the grain is at right angles to the faces of the panels.

end-grain nailing Nailing into an end-grain surface of wood so that the shank of each nail is parallel to the grain.

end house A house having one of its two ends facing the street.

end joint 1. A joint formed when boards are joined end to end, as a butt joint. 2. A joint, perpendicular to the grain, formed between two veneers. 3. A joint formed by the butt ends of two bricks which are connected with mortar.

end lap The amount of overlap in a lap joint, as at the end of a ply of roofing felt.

end lap joint An angle joint formed by two members, each of which has been cut to half its thickness and lapped over the other.

endless saw Same as band saw.

end-matched Said of boards or strips having a tongue along one end and a groove along the other.

endothermic Said of a reaction which occurs with the absorption of heat.

end post A post or a structural member which is in compression at the end of a truss.

end scarf A scarf joint between two timbers formed by the insertion of one end into the other, similar to a mortise and tenon joint.

end scroll Same as volute.

end stiffener One of the vertical angles connected to the web of a beam or girder at its ends; used to stiffen the web and transfer the end shear to the shoe, baseplate, or supporting member.

end thrust The force exerted by the end of a structural member.

endurance limit In fatigue testing, the maximum stress which can be applied to a material for an infinite number of stress cycles without resulting in failure of the material.

energized Connected to a source of voltage.

energy The capacity to do work; the amount of work that a system is capable of doing.

energy cutoff device A safety device used in a water heater to interrupt the flow of energy to the heater if the temperature or pressure exceeds a preset value anywhere within the water heating system; required by most codes to protect the water heater and to prevent possible associated equipment damage and/or loss of life.

enfilade The alignment of a series of doors axially through a sequence of rooms.

enframement Same as surround, 1.

engaged Attached (or apparently attached) to a wall by being partly embedded or bonded to it; for example, an engaged column.

engaged bollard A low post, partially incorporated in a wall or column surface; set to prevent motor vehicles from damaging the surface.

engaged column, attached column A column partially built into a wall, not freestanding.

engaged order A series of engaged columns.

engaged pier A pier, 1 that is partially built into a wall.

engaged porch Same as integral porch.

engineer A person trained and experienced in the profession of engineering; a person licensed to practice the profession by the authority in the area.

engineer-architect See architect-engineer.

engineered brick Brick having the nominal dimensions 3

in. by 4 in. by 8 in. (8.13 cm by 10.16 cm by 20.36 cm).

engineered fill Soil or crushed stone that is compacted and used as fill, 1.

engineering brick (Brit.) Brick having a dense, strong, semivitreous body conforming to these limits: Class A: compressive strength 69.0 × 10⁶ N per sq m; maximum water absorption 4.5%. Class B: compressive strength 48.5 × 10⁶ N per sq m; maximum water absorption 7%.

engineering geology The application of geology and its principles in the investigation and evaluation of naturally occurring rock and soil for use in the design of civil works.

engineering officer A person designated, usually by a military component or a corporation, as having authoritative charge over certain specific engineering operations and duties.

engineering services See building services.

engineering survey A survey conducted to obtain essential information for planning an engineering project or developing and estimating its cost.

engineer-in-training A designation prescribed by statute for a person qualified for professional engineering registration in all respects except the required professional experience.

engineer’s chain A distance measuring device used in land surveying consisting of a series of links; in the US, each link is 1 ft long; the length of the chain is 100 ft.

engineer’s level Any of a group of precision leveling instruments for establishing a horizontal line of sight; used to determine differences of elevation.

engineer’s scale A straightedge, divided uniformly into multiples of 10 divisions per inch so that drawings may be made with decimal values of distances, loads, forces, etc.

English barn 1. A timber-framed barn built of wood or stone, usually connected to the house through a series of outbuildings. 2. Same as Yankee barn.

English basement In the United States, the lowest floor of a residential building that is partly below, but mostly above, grade; the principal entrance to the building is at the level of the floor above.

English bond A brickwork pattern in which courses of headers and courses of stretchers alternate; forms a strong bond and is easy to lay.

English cottage A term occasionally used as a synonym for cottage orné.

English cross bond, Saint Andrew’s cross bond Similar to English bond, but the stretchers, in alternating courses, have their joints displaced by half the length of a stretcher.

English frame house In colonial America, particularly along the mid-Atlantic coast in the middle and latter part of the 17th century, a timber-framed house whose construction followed the then-current traditional framing techniques used in England of massive timbers with very strong joints.

English gambrel roof A gambrel roof in which the upper and lower slopes are of approximately equal length, but the lower slope is of much steeper pitch, usually about 60 degrees.

English garden An informal garden whose plantings, walks, and pools do not form any recognizable plan and are deliberately lacking in symmetry. As a supposed imitation of natural scenery, paths tend to be sinuous rather than straight, and trees and bushes are casually arranged; the antithesis of a formal garden.

English garden wall bond Like common bond except that headers occur every fourth course.

English half-timbered style See Neo-Tudor.

English log house A one-room log cabin, square in plan, having an exterior gable-end chimney; one exterior door is centered on the façade of the house and another door is centered on the rear wall.

English one-bay house In the 17th century, a house in America which had a one-room plan; widely used by English immigrants.

English Regency See Regency Revival and Regency style.

English Revival, English Tudor style See Tudor Revival and Neo-Tudor.

English tile A single-lap, flat, smooth roofing tile having interlocking sides.

ENGR On drawings, abbr. for “engineer.”

engrailed Scalloped with concave lines; cut along the edge with a series of small concave curves, usually of the same size.

engraved glass Glass whose surface has decorative designs, often produced by abrading its surface with a diamond point, copper wheel, or carborundum pencil.

ENGRG On drawings, abbr. for “engineering.”

enlucido In Spanish architecture and its derivatives, a term descriptive of a surface that is plastered.

enneastyle A term descriptive of a portico having nine columns in the front.

enplecton Greek or Roman masonry consisting of cut stone facings with an infilling of rubble.

enriched Having embellishment. Also see entail.

enrockment Same as riprap.

ENT See electrical nonmetallic tubing.

entablature 1. In Classical architecture and its derivatives, an elaborate horizontal band and molding supported by columns; horizontally divided into three basic elements: architrave (the lowest member), frieze (the middle member), and cornice (the uppermost member). The proportions and detailing of an entablature are different for each order, and are strictly prescribed. 2. Any similar construction that crowns a wall, window, or doorway.

entablement 1. The platform which is above the dado in a pedestal. 2. An entablature.

entail 1. Engraved or carved work. 2. Intaglio; inlay.

entasis The intentional slight convex curving of the vertical profile of a tapered column; used to overcome the optical illusion of concavity that characterizes straightsided columns.

enterclose A passageway between two rooms or spaces in a building.

entrained air Microscopic air bubbles intentionally incorporated in mortar or concrete during mixing, typically 10 to 1,000 µ in diameter and nearly spherical.

entrainment See secondary air motion.

entrance The point of entry into a building: an exterior door, a vestibule, or a lobby.

entrance cap Same as service head.

entrance hall A large vestibule or hall at the main entryway to a Georgian style home; usually high-ceilinged and well-lighted; commonly subdivided by an elliptical arch into two rooms: a reception hall, and a stair hall that contains an elaborate open-string staircase.

entrapped air, accidental air Voids in concrete, usually 1 mm or more in diameter, resulting from air not purposely entrained.

entrelacs See interlace.

entresol See mezzanine, 1.

entry An entrance, small hall, or vestibule inside an exterior door.

entryway An entrance passage. Also see entry.

envelope 1. The imaginary shape of a building indicating its maximum volume; used to check the plan and setback (and similar restrictions) with respect to zoning regulations. 2. The folded-over, continuous edge formed by turning the lowest ply of a built-up roofing membrane over the top surface layer; prevents bitumen from dripping through the exposed edge joints and seepage of water into the insulation.

envenomation The process by which deterioration occurs in the surface of a plastic close to or in contact with another surface; softening, discoloration, mottling, crazing, or similar effects may result

environment See built environment and natural environment.

environmental assessment A review of the probable environmental consequences of a proposed action, often performed to determine whether an environmental impact statement is required.

environmental design professions The professions collectively responsible for the design of man’s physical environment, including architecture, engineering, landscape architecture, urban planning, and similar environment-related professions.

environmental impact statement A detailed analysis of the probable environmental consequences of proposed federal legislation, major federal actions, or large-scale construction making use of federal funds, likely to have significant effects on environmental quality; such a statement is required by the National Environmental Policy Act of 1969 (42 U.S.C. §4321 et seq.).

environmental load A load, 1 on a structure usually caused by natural forces such as wind, rain, snow, earthquakes, or extreme temperatures.

Environmental Protection Agency (EPA) A governmental agency whose mission is to protect the natural environment by enacting and enforcing regulations concerning conditions that could otherwise adversely affect public health, such as the release of pollutants.

environmentally friendly Said of a process or product that is not destructive to the environment.

environmentally sensitive area A place that is vulnerable to a negative environmental impact, such as a flood plain, a wetland, an area where noise levels are excessively high, or an EPA-designated plant, fish, and animal habitat.

ephebeion A type of Greek gymnasium.

epaule In a medieval fortification, a corner of a bastion where the face, 1 and flank meet.

épi The spire-shaped termination of a projecting point or angle of a roof.

epicranitis, epikranitis 1. A molding marking the top of a wall or forming the top member of a cornice. 2. An interior cornice.

epinaos See opisthodomos.

episcenium Same as episkenion.

episkenion, episcenium distegia The upper story of the scene building in an ancient Greek or Roman theater.

epistle side In a church, the right side of an altar as one faces the altar.

epistomium In ancient Rome, a cock or faucet of a water pipe.

epistyle, epistylium An architrave.

epithedes The upper member of the cornice of an entablature.

epiurus In ancient Roman construction, a wood peg used as a nail.

epoxy A class of synthetic, thermosetting resins which produce tough, hard, chemical-resistant coatings and excellent adhesives.

epoxy joint In masonry, a visible joint filled with epoxy resin in place of mortar or caulking.

epoxy mortar A mixture of a fine aggregate, epoxy resin, and a catalyst.

epoxy paint A paint in which thermosetting resins are contained in a vehicle that results in a tough, very hard, chemically resistant coating; its components must be mixed immediately prior to use.

epoxy resin A high-strength low-shrinkage polymer, especially designed for use in construction as an adhesive, a coating, or a foam.

epoxy weld In cut-stone fabrication, a joint at an inside angle, cemented by an epoxy resin, to form an apparent single unit between two pieces of stone.

épure A full-scale, detailed drawing.

EQ On drawings, abbr. for “equal.”

equalized settlement The design of a foundation on the basis of equal settlement under a dead load, rather than uniform bearing pressure under a total load.

equalizing bed Material (such as crushed rock) laid beneath a pipeline in a trench to provide a uniform support for the pipeline.

equilateral arch, equilateral pointed arch, three-pointed arch A two-centered arch in which the chords of the curves just equal the span of the arch.

equilateral roof A roof with sides sloping at 60°, forming an equilateral triangle in cross section.

equilibrium The state of being equally balanced; a state of a body in which the forces acting on it are equally balanced.

equilibrium moisture content The moisture content of a material that is stabilized at a given humidity and temperature.

EQUIP. On drawings, abbr. for “equipment.”

equipment ground 1. In electric wiring, a connection from the exposed metal parts of equipment housings to provide a path to ground in the event such parts become energized as a result of failure of the insulation of a conductor housed within the equipment; a ground connection to any noncurrent-carrying metal parts of a wiring installation or equipment, or both. 2. A ground connector to (a) noncurrent-carrying metal parts of electrical equipment or (b) the metallic shields of a wiring installation, or both.

equipment regulator In gas supply services, same as appliance regulator.

equity The value of an owner’s interest in property, computed by subtracting the amount of outstanding mortgages or liens from the total value of the property.

equivalent continuous sound level, average sound level (L_eq) The sound level, expressed in decibels, of a steady sound which has the same A-weighted sound energy as the time-varying sound over the averaging period.

equivalent duct diameter The diameter of a round duct having approximately the same area as a rectangular duct; approximately equal to the square root of the product of the duct width times the duct height.

equivalent embedment length The length of embedded reinforcement which can develop the same stress as that which can be developed by a hook or mechanical anchorage.

equivalent round The diameter of a circle having a circumference equal to the outside perimeter of other than round tube.

equivalent temperature An index similar to effective temperature, but not considering the effects of humidity.

equivalent thickness In a hollow masonry unit, the thickness which the hollow masonry unit would have if it had no voids but had the same mass.

equivalent uniform load A conventionalized representation of an element of dead load or live load; used for design purposes in lieu of the actual load.

equiviscous temperature The temperature at which a bitumen attains the proper viscosity for built-up roofing application.

Erechtheum A temple on the Acropolis in Athens; the most important monument of the Ionic style, including a fine example of a porch of caryatides.

erection The hoisting and/or installing in place of the structural components of a building, usually using a crane, hoist, or other powered equipment.

erection bolt A bolt in the form of a threaded rod with a head at one end, used to join structural components temporarily.

erection bracing Bracing which is installed during erection, to hold framework in a safe condition until sufficient permanent construction is in place to provide full stability.

erection drawing One of the drawings (together with instructions) which is provided by a manufacturer in sufficient detail to assure that all parts of a system can be erected properly.

erection stress Stress which is induced by loads applied during erection of a structure.

erection tower At a construction site, a temporary framework used in hoisting building components or equipment.

ergastulum A Roman workhouse for slaves or debtors.

erosion 1. The deterioration brought about by the abrasive action of fluids or solids in motion. 2. The gradual deterioration of a paint film due to degradation of the binder, which results in chalking, or to mechanical abrasion, such as foot traffic.

erratum A correction of a printing, typographical, or editorial error.

errors and omissions insurance See professional liability insurance.

ERW Abbr. for electric resistance welding.

escalator, moving staircase, moving stairway A power-driven, inclined, continuous stairway used for raising or lowering passengers.

escape The curved part of the shaft of a column where it springs out of the base; the apophyge, 1.

escape hatch A means of escape from within the interior of a building, usually through a breakable or movable panel.

escape lighting Lighting provided by an independent, self-contained source of light that activates when there is failure in the normal source of electric power.

escape stair, fire-escape stair An interior or exterior stair, required by law, which provides an escape route in the event of fire.

escape route In case of emergency, a way of travel from any point within a building to the exterior and a place of safety. Also see fire escape.

escarpment A steep slope in front of a fortification to impede the approach of an enemy.

escayola A type of hard plaster or stucco.

escheat The assumption of ownership of property by the state if no other owner can be found.

esconson Same as sconcheon.

Escorial A palace of the kings of Spain, built by Philip II in the 16th cent. near Madrid.

escrow A legal device used in a construction contract whereby something of value is placed with a third party, acting as a trustee, to guarantee that conditions of the contract will be met.

escutcheon 1. A protective plate surrounding the keyhole of a door, a light switch, etc.; also called a scutcheon. 2. A flange on a pipe, used to cover a hole in a floor through which the pipe passes. 3. A protective or ornamental cover at the termination of a post, picket, or rail against a tread, floor, or wall.

escutcheon pin A small nail, usually brass, used for fixing an escutcheon; often ornamental.

esonarthex The second narthex from the entrance, when two are present.

esp. Abbr. for “especially.”

espadaña In Mission architecture, a decorative gable end of a church having a multicurved mission parapet; the gable end often has a false front, designed to be impressive; it usually does not house a bell.

espagnolette bolt Same as cremone bolt.

espalier 1. A trelliswork of various forms on which the branches of fruit trees or fruit bushes are extended horizontally, in fan shape, etc., in a single plane, to secure a freer circulation of air for the plant and better exposure to the sun. 2. A tree or plant so grown.

esplanade A level open space for walking or driving, often providing a view.

esquisse A first sketch or very rough design drawing showing the general features of a project.

essential facility A facility in a building that must remain functional for the public good in the event of a major disaster, such as a severe earthquake.

Essex board measure On a special type of steel square used by carpenters, a chart which lists the number of board feet in a board 1 in. thick and of various standard sizes.

EST On drawings, abbr. for estimate.

estate 1. The property of a deceased at the time of death. 2. A property interest, usually applied to land.

estimate 1. See detailed estimate of construction cost. 2. See statement of probable construction cost. 3. See contractor’s estimate.

estimated design load In a heating or air-conditioning system, the sum of the useful heat transfer, plus heat transfer from or to the connected piping, plus heat transfer occurring in any auxiliary apparatus connected to the system.

estimated maximum load In a heating or air-conditioning system, the calculated maximum heat transfer that the system may be called upon to provide.

estimator A person who, by experience and training, is capable of estimating the probable cost of a building or portion thereof.

estípite In Spanish and Latin-American Mannerist architecture and derivatives, a shaft of square cross section, tapering downward, frequently combined with other unusual elements, the whole used like an order.

estlar Old English term for ashlar.

estrade A platform or dais.

etch 1. To cut away the surface of glass or metal with a strong acid or by abrasive action, usually in a decorative pattern. 2. To remove the surface of cast stone with acid to expose the aggregate. 3. To alter the surface texture of porcelain enamel by chemical attack.

ethylene glycol A type of alcohol, completely miscible in water, used in latex and water-based paints to provide stability when frozen; used in heating and cooling systems as a fluid for transferring heat.

ETL Abbr. for “Electrical Testing Laboratories, Inc.”

Etruscan architecture The architecture of the Etruscan people in western central Italy from the 8th century B.C. until their conquest by the Romans in 281 B.C. Apart from some underground tombs and city walls, it is largely lost, but remains important for the influence of its construction methods on Roman architecture, e.g., the stone arch.

ettringite A mineral, high in sulfate calcium sulfoaluminate; occurs naturally or is formed by sulfate attack on mortar and concrete; designated as a cement bacillus in older literature.

eucalyptus Wood of the eucalyptus tree, native to Australia and Tasmania, but many species now are grown elsewhere in the world; the physical characteristics and properties vary considerably with the species. Also see gumwood.

eucharistic window Same as squint, 1.

euripus 1. In ancient Rome, any artificial pond or canal used to ornament a villa. 2. A ditch around the arena of an amphitheater of a circus to prevent wild animals from escaping.

eurythmy Harmony, orderliness, and elegance of proportions.

eustyle See intercolumniation.

euthynteria The top course of the foundation of a Classical Greek temple; used to eliminate irregularities in the foundation.

EV1S Abbr. for “edge vee one side.”

evaporable water Water in set cement paste which is present in capillaries or held by surface forces; measured as that water which is removable by drying under specified conditions.

evaporation Loss of vaporized water, solvent, etc., as from a paint film.

evaporation retarder An organic liquid which, when spread on the water film on a concrete surface, retards the evaporation of water resulting from bleeding, 5.

evaporative cooling Cooling accomplished by evaporating water (usually as a fine spray) in air; as a result, the dry-bulb temperature decreases and the humidity increases; this principle is used in cooling towers and in the cooling of buildings in hot, arid climates.

evaporative cooling tower See cooling tower.

evaporative equilibrium, true wet-bulb temperature The condition attained when the wetted wick of a wet-bulb thermometer has reached a stable and constant temperature when exposed to moving air in excess of 900 ft (274.3 m) per minute.

evaporator That part of a refrigeration system in which cooling is produced by evaporation of the liquid refrigerant, thereby absorbing heat and resulting in cooling.

evasé Opened out, flared.

event In a CPM arrow diagram, the starting point for an activity; occurs only when all work preceding it has been performed.

even-textured Descriptive of wood of uniform texture with little difference in cell size between springwood and summerwood.

evergreen Said of a plant or tree that retains its verdure through all the seasons, as the pine and other coniferous trees, the holly, rhododendron, etc.

eviction Removal of a tenant from property. Eviction may be lawful, pursuant to authorization contained in the lease; it may be warranted by breaches on the part of the tenant, such as nonpayment of rent, or by other factors such as expiration of the lease by its own terms. Unlawful eviction normally will give the tenant a right to damages and in appropriate cases a right to be restored to possession of the property. Also see constructive eviction.

exastyle Same as hexastyle.

EXC On drawings, abbr. for “excavate.”

excavation 1. The removal of earth from its natural position. 2. The cavity resulting from the removal of earth.

excavator Any of a number of power-driven machines used to dig, move, and transport earth, gravel, etc.

exceedance probability The probability of a storm occurring during any one year which equals or exceeds the rainfall rate used in the design of the storm-water drainage system.

excelsior, wood wool Curly, fine shavings cut from wood.

excess condemnation Condemnation of more property than is required for a specific public improvement.

excess current Same as overcurrent.

excess joint A joint in brickwork in which more mortar is applied in laying the joint than is required for a satisfactory masonry bond. Some of the mortar projects beyond the face of the wall, resulting in an irregular surface and, therefore, relatively poor weather protection at the mortar joint.

exchequer To use or have a pattern of checkers.

exclusionary provision In an insurance policy covering potential losses on a building, a provision that excludes certain types of losses from the coverage provided.

excubitorium 1. A gallery in a church where public watch was formerly kept at night on the eve of a festival. 2. In a medieval monastery, an apartment for night watchers whose duty it was to call monks to their nocturnal devotions.

exedra, exhedra 1. A large niche or recess, usually with a bench or seats, semicircular or rectangular in plan and either roofed or unroofed. 2. In a church, a large apsidal extension of an interior volume, normally on a main axis.

exfiltration 1. The outward flow of air through a wall, joints, etc. 2. In a sewer pipeline, the volume of flow leaving a pipeline into the surrounding soil.

exfoliated vermiculite Vermiculite which has been expanded, by a heat process, to many times its original volume; suitable for lightweight aggregate, particularly for insulating purposes; used as a thermal insulation.

exfoliation Peeling, swelling, or scaling of stone or mineral surfaces in thin layers; caused by chemical or physical weathering or by heat. Minerals such as vermiculite expand to many times their original size when heat-treated.

EXH On drawings, abbr. for “exhaust.”

exhaust air The air that is removed from an air-conditioned space and discharged to the outdoors.

exhaust-air grease extractor See grease extractor.

exhaust fan A fan which withdraws air from a localized area or from a space in a building from which it is desired not to return the air to the central air-treatment system, as from a toilet.

exhaust fume hood A prefabricated cabinet angular which confines odoriferous, poisonous, or corrosive fumes for exhausting or filtered recirculation; esp. used in laboratories.

exhaust grille A grille through which air is exhausted from a conditioned space to the atmosphere.

exhaust-heat recovery system See waste-heat recovery system.

exhaust hood A protective hood over an area (such as a kitchen stove) from which fumes and heated air may be removed by an exhaust fan set within the hood.

exhaust opening An exhaust grille or any type of opening through which air is exhausted from a space.

exhaust shaft An outlet duct from an exhaust fan through which foul air or gases are expelled to the atmosphere.

exhaust ventilation The removal of foul air from a space by a mechanical means, such as a fan; fresh air is allowed to enter through available or controlled openings.

EXIST. On drawings, abbr. for “existing.”

existing building In regulations and in codes, a building which is already completed or which may be built under prior laws or regulations.

existing grade The grade, 2 prior to excavation or filling.

existing work In regulations and in codes, such as a utility service or a system (or any part thereof) installed prior to the effective date of the applicable regulations or code.

exit That portion of a means of egress which is separated from the rest of a building by walls, floors, doors, or other means and which provides a reasonably protected path of escape for the occupants of a building in the event of fire.

exit access That portion of a means of egress which leads to an exit.

exit corridor A corridor or enclosed passageway connecting a stairway, fire tower, or other required exit with a street or alley or with an open space communicating with a street or alley.

exit court A yard or court providing egress to a public way for one or more required exits.

exit device See panic exit device.

exit discharge That portion of a means of egress between the termination of the exit at the exterior of a building and the ground level.

exit door A door that leads to an escape route to the exterior in case of fire; the door must carry an exit sign that conforms with the applicable code.

exit light An illuminated sign used to identify an exit.

exit passageway An enclosed means of egress connecting a required exit or exit court with a public way.

exonarthex The narthex nearest the entrance, when two are present.

exostes A loggia having a balcony.

exothermic Said of a reaction that occurs with the evolution of heat.

exotic plant A plant that is not native to the locality or region in which it is being grown.

Exotic Revival, Exotic Eclectic A term descriptive of architecture based loosely on exotic prototypes, moderately popular primarily from about 1835 to 1890. See Egyptian Revival, Moorish Revival, Oriental Revival, Swiss Cottage architecture.

expanded blast-furnace slag, foamed blast-furnace slag The lightweight cellular material obtained by controlled processing of molten blast-furnace slag with water, or with water and other agents such as steam or compressed air or both. Also see blast-furnace slag.

expanded cement See expansive cement.

expanded clay Clay which has been heated to a semiplastic condition and expanded to many times its original volume by the formation of internal gas; used as a lightweight aggregate.

expanded corner bead A corner bead having wide expanded flanges that are easily flexed; provides increased reinforcement.

expanded glass See foam glass.

expanded metal A type of metal lath having an open mesh formed by slitting metal sheet; made in various patterns and metal thicknesses, with either a flat or an irregular surface.

expanded-metal lath A metal lath used as a base on which to apply plaster; usually fabricated by slitting sheet metal and then stretching it to form openings through which plaster is troweled; the lath holds the plaster coat firmly in place.

expanded-metal partition A partition formed of heavy expanded-metal lath on thin framing or support members, both sides of which are plastered to form a solid assembly, usually about 1½ to 2½ in. (3.8 to 6.4 cm) thick.

expanded perlite A natural, volcanic, glassy, light, cellular material suitable for lightweight aggregate in concrete.

expanded plastic 1. See cellular plastic. 2. See foamed plastic, 1.

expanded polystyrene A foamed styrene plastic; has high resistance to heat flow; mechanical strength relatively high for such a light material.

expanded polyurethane A type of expanded foamed plastic that is commonly used as thermal insulation in a cavity wall; some types of foamed plastic can be formed at the site.

expanded rubber Cellular rubber having closed cells, made from a solid rubber compound.

expanded shale Shale which has been heat-treated so that it expands to many times its original volume; used as a lightweight aggregate.

expanded slate Slate which has expanded to many times its original volume as a result of exfoliation; this heating process causes the formation of internal gas, producing a porous structure which is retained upon cooling so the material is suitable as a lightweight aggregate.

expanding bit Same as expansion bit.

expanded vermiculite Same as exfoliated vermiculite.

expanding cement Same as expansive cement.

expanding pile A pile provided with a mechanical device at its lower end to expand the bottom so as to provide greater bearing and a higher resistance to uplift.

expanding vault A conical vault.

expansion The increase in length or volume of a material, or a body, caused by temperature, moisture, or other environmental condition.

expansion anchor Same as expansion bolt.

expansion attic An unfinished attic in a completed house, capable of being converted into livable area.

expansion bearing A support at the end of a span where provision is made for the expansion and contraction of the structure.

expansion bend, expansion loop A bend (usually in the form of a horseshoe or Ω) which is inserted in a pipe run to provide for the expansion of the pipe resulting from a temperature change.

expansion bit, expansive bit A bit, of adjustable size, for cutting holes in wood. (See illustration p. 380.)

expansion bolt An anchoring device having an expandable socket that swells as a bolt is tightened into it; used in masonry walls for attaching timber, etc.

expansion coefficient See coefficient of expansion.

expansion coil An evaporator constructed of pipe or tubing.

expansion-compression joint Same as expansion joint.

expansion fastener Same as expansion bolt.

expansion fitting See expansion bend.

expansion joint 1. A joint or gap between adjacent parts of a building, structure, or concrete work which permits their relative movement due to temperature changes (or other conditions) without rupture or damage. 2. An expansion bend.

expansion joint cover A prefabricated cover which serves to protect an expansion joint, 1; designed to accommodate relative movement between the surfaces on the two sides of the joint.

expansion joint filler See joint filler, 2.

expansion loop See expansion bend.

expansion shield Same as expansion bolt.

expansion sleeve A pipe sleeve which permits movement of the element that it houses.

expansion strip Material in an expansion joint.

expansion tank A tank in a hot-water heating system, above the heating tank, which allows for the increased volume of water when heated.

expansion valve In a refrigeration system, a valve for controlling the flow of refrigerant to the cooling element.

expansive bit See expansion bit.

expansive cement, sulfoaluminate cement A cement which when mixed with water forms a paste that tends to increase in volume, after setting, to a significantly greater degree than portland cement paste does; used to compensate for volume decrease due to shrinkage or to induce tensile stress in reinforcement. Classified as Type K: Contains anhydrous aluminosulfate burned simultaneously with a portland cement composition, or burned separately when it is to be inter-ground with portland cement clinker or blended with portland cement, calcium sulfate, and free lime. Type M: A mixture of portland cement, calcium aluminate cement, and calcium sulfate. Type S: A portland cement containing a large computed tricalcium aluminate content, modified by an excess of calcium sulfate above usual optimum content.

expansive-cement concrete Concrete made with expansive cement in order to reduce or control volume changes during the curing period. Also see self-stressing, shrinkage-compensating.

expansive hydraulic cement A hydraulic cement that forms a paste when mixed with water, thereby increasing in volume by a controlled amount during the early hardening period which occurs after setting.

expansive soil Soil that tends to increase in volume as a result of an increase in its water content.

EXP BT On drawings, abbr. for expansion bolt.

expert witness A witness in a court case or other legal proceeding, or in an arbitration proceeding, who, by virtue of his experience, training, skill, and knowledge of a particular field or subject, is recognized as being especially qualified to render an informed opinion on matters relating to that field or subject.

expiatory chapel A chapel erected to expiate a murder or other great crime.

expletive Something used to fill up, as a piece of masonry used to fill a cavity.

exploded view A drawing, rendering, or the like showing the individual disassembled components of an apparatus, device, or machine; the parts are shown in their proper relationship with respect to their assembled position.

exploration The general activity undertaken to identify and classify the elements of which a soil mass is constituted.

explosion-proof Said of an enclosure that is capable of withstanding an explosion of a specified gas or vapor that may occur within it, and of preventing the ignition of the gas or vapor surrounding it.

explosive Any explosive chemical compound, mixture, or device, the primary or common purpose of which is to produce an explosion; i.e., with substantially instantaneous release of gas and heat, unless such compound, mixture, or device is otherwise specifically classified by the US Department of Transportation. Class A: possessing detonating hazard, such as dynamite or nitroglycerin. Class B: possessing flammable hazard, such as propellant explosives. Class C: containing class A or class B explosives, but in restricted quantities.

explosive actuated gun See stud gun.

explosive rivet A rivet having an explosive-filled, hollow shank; the rivet is inserted, then the shank is exploded by striking it with a hammer.

exposed 1. Said of an electrically live part which can be touched or approached nearer than a safe distance by a person; not suitably guarded, isolated, or insulated. 2. Said of a system (such as gas piping or electrical wiring) which is visible in the finished structure.

exposed-aggregate finish A decorative finish for concrete work; achieved by removing the outer skin of mortar, generally before the concrete has fully hardened, and exposing the coarse aggregate.

exposed finish tile Tile whose surfaces are intended to be left exposed or painted; tile may be smooth, combed, or roughened.

exposed masonry Any masonry construction having no surface finish other than paint applied to the wall face.

exposed nailing See nailing.

exposed suspension system, grid system A system for suspending an acoustical ceiling in which the members supporting the acoustical material are visible in the room.

exposure Of a wood shake: same as weather, 1.

exposure hazard The probability that a building will be exposed to fire in surrounding or adjoining property.

exposure line An imaginary line drawn across a wood shake, dividing it so that the area above this line is the same area as that below it; the area below the line is that portion of the shake exposed to the weather.

expulsion fuse A fuse that uses the gases produced by an arc and the lining of the fuse holder to extinguish the arc produced when the fuse melts.

EXT On drawings, abbr. for “exterior.”

extended-care facility An institution in which resident patients receive medical, nursing, and rehabilitative services for medical conditions less acute than those normally cared for in a general hospital. May be an independent building or a designated portion of a hospital.

extended coverage insurance 1. See property insurance. 2. See steam boiler and machinery insurance.

extended coverage sprinkler In a fire sprinkler system, a type of spray sprinkler (i.e., sprinkler head) which extends the usual maximum area of protection; listed as a special sprinkler.

extended pigments An organic pigment that has been diluted with an extender (e.g., calcium carbonate or blanc fixe).

extended-service lamp See long-life lamp.

extended surface Additional surface on a pipe or tube used in heat transfer, usually consisting of metal fins, disks, pins, or ribs.

extender 1. A white, inert mineral pigment of low opacity; used in paints to provide bulk, texture, or a lower gloss or to reduce paint cost. Common extenders are calcium carbonate, silica, diatomaceous earth, talc, and clay. 2. A substance added to synthetic resin adhesives to increase volume and reduce cost without affecting quality.

extensibility The capacity of a sealant to be stretched in tension.

extension A wing or structure added to an existing building.

extension bolt Same as extension flush bolt.

extension casement hinge On a casement window which has a sash (ventilator, 2) that swings outward, an exterior hinge so located that when the window is open clearance is provided on the hinge side to permit cleaning from the inside.

extension device Any device (excluding an adjustment screw) used to obtain vertical adjustment.

extension flush bolt A type of flush bolt; bolt head is connected to the operating mechanism by a rod inserted through a hole bored in the door.

extension ladder A ladder which has more than one section, each sliding within the other, so that it can be extended in length.

extension link A hardware device used to provide a long backset in the bored lock of a door.

extension rule A rule containing a calibrated sliding insert which may be extended.

extension trestle ladder A ladder which is self-supporting and adjustable in length; consists of a trestle ladder base and a vertically-adjustable single ladder which may be interlocked.

exterior balcony A landing or porch projecting from the wall of a building.

exterior chimney, external chimney A chimney located outside, and usually attached to, an exterior wall of a house at the gable end, gambrel end, or mansard end.

exterior corner reinforcement A preformed section of expanded sheet metal used to reinforce exterior stucco or plaster corners.

exterior door A door that connects the interior of the building with the exterior.

exterior finish The outer finish of a building which provides protection against weather or serves as a decorative element.

exterior glazed Said of glazing that has been set from the outside of the building.

exterior insulation and finishing system An exterior finish for a building composed of polystyrene foam covered with a synthetic stucco; this type of stucco (in contrast to traditional, porous cement-based stucco) is waterproof and is sprayed on.

exterior paint A paint with durable binder and pigments especially formulated to withstand exposure to weather.

exterior panel One of the panels of a flat concrete slab having at least one edge which does not join another panel.

exterior plywood A structural glue-laminated timber that is made of three or more plies (usually an odd number); the glue must be waterproof.

exterior ramp A ramp, 1 that is an appendage to a building, leading to a level above or below existing ground level.

exterior separation The distance from the outermost exterior wall of a building to the center line of an adjacent street or public space, or to an interior lot line, or to a line halfway between the exterior wall and the wall of another building on the same lot.

exterior stair A stair exposed to the outdoors; often it is a legally required exit.

exterior trim Any material applied to an exterior wall that, if removed or destroyed, will not reduce the structural stability of the building enclosure, and that is installed so as not to reduce the required fire-resistance rating of the enclosure. May include belt courses, cornices, fascias, gutters, half-timber work, overhanging eaves, shutters, surrounds, trellises, and moldings around doors and windows; does not include door and window frames and sashes.

exterior-type plywood Plywood bonded with a fully waterproof glueline.

exterior wall, external wall, periphery wall A wall which is part of the envelope of a building, thereby having one face exposed to the weather or to earth.

external dormer See dormer window.

external leaf The leaf of a cavity wall which faces the exterior.

external thread Same as outside thread.

external vibration Energetic agitation of freshly mixed concrete by means of a vibrating device which is attached at selected positions on the concrete forms.

external wall See exterior wall.

EXTR On drawings, abbr. for “extrude.”

extra Performed work or a desired item of construction which is beyond the intent of the drawings and specifications contained in a construction contract; an item of work, 1 involving additional cost. Also see addition, 3.

extractives Substances in wood such as colorants, oils, tannins, resin, etc., that are not an integral part of the cell structure and can be removed with solvents.

extrados The exterior curve or boundary of the visible face of the arch.

extradosed arch One which has the extrados clearly marked, as a curve exactly or nearly parallel to the intrados; has a well-marked archivolt.

extra heavy Said of a piping (usually cast iron) that is thicker than standard.

extra-high-pressure mercury lamp A mercury-vapor lamp that operates at a partial pressure of about 10 atmospheres or higher.

extra-rapid-hardening cement See high-early-strength cement.

extra services See additional services.

extra-strong pipe A standard designation for steel or wrought-iron pipe in which the wall thickness is greater than that of standard-weight pipe.

extra work Any work not included in the contract documents; an extra.

extruded brick See wire-cut brick.

extruded compactor A type of refuse compactor that produces a continuously extruded cylinder of compacted refuse in a plastic casing, in a manner similar to that of sausage packed into a sausage casing. The casing is cut and sealed in convenient lengths for ease of handling.

extruded corner A bay projecting where two masses of an edifice form a reentrant angle, and hence a convenient location for stairs.

extruded joint In masonry work, a seldom-used term for excess joint.

extrusion 1. The process of producing metal shapes of a constant cross section by forcing the hot metal through an orifice in a die by means of a pressure ram. 2. Any item made by this process.

extrusion coating A thin film of molten resin which has been extruded and pressed onto a substrate to form a coating without an adhesive.

exudation Any liquid or liquid-like material which oozes through a pore, crack, or opening in a concrete surface.

eye 1. The central roundel of a pattern or ornament. 2. The circular (or nearly circular) central part of a volute, as in an Ionic capital. 3. One of the smaller, more or less triangular, openings between the bars of Gothic tracery. 4. An oculus, esp. one at the summit of a dome. 5. A hole through material for access, to permit the passage of a pin, or to serve as a means of attachment.

eyebar A bar with an eye at either one end or each end; used as a tension member in a steel truss; a pin passes through the eye, forming a joint.

eyebolt A bolt having its head in the form of a loop or eye.

eyebrow, eyebrow dormer A low dormer that has no sides, the roofing courses being carried over the dormer in a continuous wavy line.

eyebrow eave On a shingled roof, an eave that is carried over a door entry in a continuous wavy line.

eyebrow lintel A lintel above a window, carried over the window in a continuous wavy line.

eyebrow monitor See trapdoor monitor.

eyebrow window 1. A bottom-hinged, inward-opening window in the uppermost level of a house, usually under the front eaves; often one of a series of windows in the frieze of a Greek Revival style building. 2. A window in an eyebrow.

eye-catcher See folly.

eye-house See I-house.

eyelet 1. In a medieval castle, a small opening for light, air, or the discharge of missiles, in a wall or parapet; a small loophole. 2. A small hole in a wall.