G

gable 1. A vertical surface commonly situated at the end of a building, usually adjoining a pitched roof; its shape depends on the type of roof and parapet, although most often it is triangular; often extends from the level of the cornice up to the ridge of the roof. If the gable is on the façade rather than the back end, the building is said to be front-gabled. 2. A similar end that is not triangular in shape; for example, a gambrel end (US). For definitions and illustrations for particular types see bell gable, broken gable, clipped gable, corbie gable, corbiestep gable, cross gable, crowfooted gable, crowstep gable, curvilinear gable, docked gable, Dutch gable, end gable, façade gable, Flemish gable, front-gabled, hanging gable, intersecting gable, multicurved gable, parapet gable, segmental gable, side gable, stepped gable, straight-line gable, truncated gable, tumbled-in gable, wall gable.

gableboard See bargeboard.

gable coping The protective cap covering a gable wall that projects above the line of the roof finish.

gable dormer, gabled dormer Same as triangular dormer.

gable elbow A single step at the base of a straight-line gable.

gabled roof See gable roof.

gabled tower A tower finished with a gable on two sides or on all sides, instead of terminating in a spire, or the like.

gable end A wall of a building having a gable at its end; a gable wall; also called a gable-end wall.

gable finish The molding or cornice around a gable end, usually on the eaves of a building.

gable front A façade that is front-gabled.

gable-front-and-wing plan The plan of a house having its long side perpendicular to the street and having a gable on the end facing the street; a wing is added at the rear of the house.

gable-fronted Same as front-gabled.

gable-on-hip roof A hipped roof in which the hips are not carried all the way to the ridge; instead, each end roof surface turns vertically near the top so as to form a small gable that is perpendicular to the ridge.

gable ornamentation Any type of decorative element on the face of a gable, such as spindle-work, near the apex of a gable.

gable post A short post located at the peak of a gable into which the bargeboards are fixed.

gable roof A roof having a single slope on each side of a central ridge; usually with a gable at one or at both ends of the roof.

gable shoulder Projecting brickwork or masonry which supports the foot of a gable.

gable springer, skew block, skew butt A kneeler, 1 (esp. a projecting one) which is at the foot of a gable or the like.

gablet A small ornamental gable.

gable vent A louvered opening in the gable of a roof; used to exhaust air from an attic.

gable wall A wall which is crowned by a gable.

gable window 1. A window in a gable. 2. A window shaped like a gable.

gaboon, okoume A wood resembling African mahogany but softer and lighter in weight.

gadroon, godroon An ornament composed chiefly of ovoid or more elongated bosses regularly repeated, side by side.

gage See gauge.

gaged See gauged.

gaged brick See gauged brick.

gaging See gauging.

gag process The process of bending structural shapes in a gag press.

gain In carpentry, a groove or notch in one piece into which another piece is fitted.

gaine A decorative pedestal, esp. one tapered downward and square in section. Also see estípite.

gal On drawings, abbr. for “gallon.”

galería In Spanish Colonial architecture, an open, covered porch, usually arcaded, either facing a patio or the street.

galerie A gallery or porch. In French Vernacular architecture of Louisiana, a roofed porch, usually open-sided, often extending across the entire front, across the front and one or more sides, or completely around the building on the upper level.

galerie house, gallery house In French Vernacular architecture, a farmhouse or plantation house evolved by French-speaking settlers in the Louisiana Territory; usually has a roofed galerie either across the façade or across the façade and one or both sides of the house; typically has gabled dormers with windows. Also see Cajun cottage and Creole house.

galilee A narthex or chapel at the entrance of a church; often used for worship.

galilee porch A galilee that has direct communication with the exterior of a church; can be considered as a vestibule to the principal part of the church.

gall Unusual growth of plant tissues; a result of the introduction of a foreign substance such as a chemical or fungus, or a result of mechanical injury.

gallery 1. A long, covered area acting as a corridor inside or on the exterior of a building, or between buildings. 2. An elevated area, interior or exterior, e.g., minstrel gallery, music gallery, roof gallery. 3. An elevated section of the seating area of an auditorium, esp. the uppermost such space. 4. In buildings for public worship, a similar space, sometimes set apart for special uses. 5. A service passageway within a building, or linking a building underground to exterior supplies or exits. Some service galleries also serve sightseers, e.g., the lighting gallery in the base of the dome at St. Peter’s, Rome. 6. A long, narrow room for special activities like target practice, etc. 7. A room, often top-lit, used for the display of art works. 8. A building serving such art needs. 9. See long gallery. 10. Any raised working platform at the side or rear of a theater stagehouse. 11. An arcade, 2. 12. (Brit.) A device, attached to a lampholder, for supporting a reflector, shade, etc.

gallery apartment house An apartment house having external passageways which provide entry to individual apartments on each floor.

gallery grave A prehistoric burial place consisting of a long stone-lined gallery without a tomb chamber, and covered by an artificial mound.

gallet A stone chip or spall.

galleting, garreting 1. The insertion of stone chips into the joints of rough masonry to reduce the amount of mortar required, to wedge larger stones in position, or to add detail to the appearance. 2. Pieces of tile used to provide a suitable bed for ridge tile or hip tile. 3. The insertion of small pieces of flint or colored stone in soft mortar; serves as a decorative element.

gallows bracket A triangularly shaped bracket fixed to a wall, such as one to support shelving.

GALV On drawings, abbr. for “galvanize.”

galvanic anode See sacrificial anode.

galvanic corrosion An electrochemical action which takes place when dissimilar metals are in contact in the presence of an electrolyte, resulting in corrosion.

galvanize To coat steel or iron with zinc, as, for example, by immersing it in a bath of molten zinc.

galvanized iron Sheet metal of iron coated with zinc to prevent rusting; used extensively for flashings, roof gutters, gravel stops, flexible metal roofing, etc.

galvanized pipe A steel pipe or wrought-iron pipe, of standard dimensions, which has been galvanized by coating it with a thin layer of zinc.

galvanizing The process of coating steel or iron with zinc by immersing it in a bath of molten zinc.

gambrel end An end wall of a structure having a gambrel roof.

gambrel roof, gambrel 1. (US) A roof which has two pitches on each side; in Great Britain called a mansard roof. 2. (Brit.) A roof which has a small gable near the ridge on one end; the part of the roof below the gable is inclined. Also see Dutch gambrel roof, English gambrel roof, Flemish gambrel roof, New England gambrel roof, Swedish gambrel roof.

game room A room used primarily for recreation, often downstairs in a dwelling.

gamma protein Protein obtained from soya beans; used as a thickener in water-base paints.

gang boarding See cat ladder.

ganged form Prefabricated panels which are joined to make a much larger unit, for convenience in erecting, stripping, and reusing; usually braced with wales, strong-backs, or special lifting hardware.

Gang Nail A registered trademark of Gang-Nail Systems, Inc. A type of timber connector consisting of a metal plate having a series of spikes at right angles to it.

gang saw A powered assemblage of parallel reciprocating saw blades; used to cut a quarry block into slabs; generally utilizes a loose abrasive material with water, or diamond or tungsten carbide blade inserts, to effect the cutting.

gangway 1. A platform or boardwalk erected over an unfinished building section to provide access for men and materials carriers. 2. British term for aisle.

ganister A product made by mixing ground quartz with a bonding material such as fireclay.

gantry A framework, usually of heavy timbers, to support building equipment or to provide a working platform.

gantry crane A revolving crane, positioned atop a movable pedestal that travels along tracks; can reach a more extensive area of a construction site than a stationary crane of similar size.

gap An opening, as in a wall; an open joint.

gap-filling glue A glue used to join surfaces which cannot be closely fitted together.

gap-graded aggregate Aggregate having a particle-size distribution characterized by gap grading.

gap-graded concrete Concrete which contains gap-graded aggregate.

gap grading A particle-size distribution for material such as an aggregate in which particles of certain intermediate sizes are substantially absent.

gar. Abbr. for garage.

garage 1. Building or part thereof where motor vehicles are kept. 2. Place for repairing and maintaining such vehicles. Also see attached garage, detached garage.

garage door See overhead door.

garbage Animal and vegetable waste from restaurants, hotels, markets, and like installations; contains up to 70% moisture and up to 5% incombustible solids. Also see refuse, rubbish, and trash.

garbage chute See refuse chute and gravity-type refuse chute.

garbage-disposal unit Same as waste-disposal unit.

garçonnière A bachelor apartment. In French Vernacular architecture, a bachelor’s residence that is separate from the main house.

garden A plot of ground used principally for growing vegetables, fruits, or flowering and/or ornamental plants.

garden apartment 1. Ground-floor apartment with access to a garden or other adjacent outdoor space. 2. Two- or three-story apartment buildings with communal gardens, generally located in the suburbs.

garden arch An archway in a garden, often of lattice construction, that serves as a decorative structure on which to grow vines, roses, or other climbing plants.

garden city A residential development having parking areas; esp. planned to provide considerable open space that is well planted with trees and shrubs.

garden flat Same as garden apartment.

garden house A structure for shelter in a garden, usually small.

garden tile Structural ceramic units made in molds and placed as stepping stones through a garden or patio.

garden wall bond See English garden wall bond, Flemish garden wall bond, mixed garden wall bond.

garden wall cross bond In brickwork, a bond in which a course of headers alternates with a course consisting of a header followed by three stretchers.

garderobe 1. See wardrobe. 2. A small bedroom or study. 3. Euphemism for a latrine in medieval buildings.

garetta Same as garretta.

gargoyle A waterspout projecting from the roof gutter of a building, often carved grotesquely.

garland An ornament in the form of a band, a wreath, or a festoon of leaves, fruits, or flowers.

garland drain A shallow ditch or trench for draining surface or subsoil water before it reaches an excavation.

garner Same as granary.

garnet A mineral having many varieties in color and constituents but the same general chemical formula, with an isometric crystal structure.

garnet hinge Same as cross-garnet hinge.

garnet paper An abrasive paper coated with finely powdered garnet; used in finishing and polishing surfaces.

garret 1. Space within a roof structure; sometimes called an attic. 2. A room, usually with sloping ceilings, just beneath the roof of a house.

garreting See galleting.

garric bolt A tempered-steel device having a wedge-shaped termination that is fitted into a dovetailed recess in a stone block or other masonry unit for the purpose of lifting it; similar to, but smaller and stronger than, a lewis bolt.

garrison house 1. An early fortified house generally constructed of stone or hewn logs, commonly with a second-story overhang; commonly fitted with loopholes; provided a family with a safe haven of refuge in times of emergency and served as a one-family dwelling in times of peace. 2. A modern term sometimes applied to any Colonial Revival house having an overhanging second story.

garth The open courtyard of a cloister, often a lawn.

gas burner One or more holes through which a combustible gas flows and burns.

gas checking A wrinkling in a paint or varnish finish which, as it sets, is exposed to burnt coal gas.

gas concrete Lightweight concrete produced by developing voids by means of gas generated within the unhardened mix (usually from the action of cement alkalies on aluminum powder used as an admixture). Also see aerated concrete and foamed concrete.

gas distribution piping All piping from the house side of the gas meter to the consumer service pipes used to supply fuel or illumination to a building.

gaseous discharge The emission of light from gas atoms excited by an electric current.

gaseous discharge lamp A lamp that produces light by means of an electrical discharge of gas inside the bulb; the most commonly used gases are neon, helium, and xenon.

gas-filled lamp An incandescent lamp in which the filament operates in an inert gas atmosphere within the bulb.

gas-fired Heated by the combustion of gaseous fuel.

gas-fired water heater A direct-fired water heater using natural gas, manufactured gas, or propane gas as its source of fuel.

gas flow meter An instrument for measuring the velocity or volume of flowing gases.

gas furnace A furnace which uses gas as a fuel.

gasket 1. A continuous strip of resilient material attached to a door or doorframe to provide a tight seal between the door and frame; acts as weather stripping and as a light and sound seal. 2. Any ring of resilient material, used at a joint to prevent leakage.

gasket glazing Glazing which is set into an opening and held in place by an elastomeric gasket.

gasketed joint A joint utilizing a gasket under compression to join cast-iron soil pipe and ductile-iron sewer and pressure pipe. The end of each pipe must be of a type suitable for the individual joint.

gas main The line from the public utility which supplies gas to the consumer service pipes.

gas metal-arc welding An arc-welding process in which coalescence is produced by heating with an arc between a consumable electrode (of filler metal) and the work.

gas meter A mechanical instrument for measuring the amount of gas volume passing a given point.

gas-meter piping The piping from the gas service-line valve to the outlet of the gas-meter regulator in a building.

gas piping system The collective gas service piping, gas meter piping, and gas distribution piping.

gas pliers Sturdy pliers having concave jaws with serrated faces; esp. useful for gripping pipe or other round objects.

gas pocket, blowhole A hole or void, as in a casting, which results from entrained air.

gas pressure regulator A device for controlling and maintaining a uniform gas pressure; required when (a) the pressure of the gas supply is higher than the pressure at which the branch supply line or gas-utilization equipment is designed to operate, or (b) the pressure varies beyond design limits of the utilization equipment.

gas refrigeration Refrigeration involving the use of machinery in which the refrigerant is heated by a gas flame.

gas room A fully enclosed room, separately ventilated, in which toxic and highly toxic compressed gases and associated equipment and supplies are used or stored.

gas service-line valve The valve located at (or below) grade on the supply side of a gas meter or service regulator.

gas service piping The gas supply piping from the street gas main up to and including the gas service-line valve.

gas station A building or stand where fuel for motor vehicles is sold. Facilities for motor vehicle repair are often a part of the station.

gas vent A vent pipe leading to the outside air from a gas furnace or other gas-fired equipment for removal of gaseous products of combustion.

gas welding Any one of a group of welding processes in which coalescence is produced by heat from one or more gas flames; sometimes a filler metal is used; pressure may or may not be applied to the materials being welded.

gatch Plaster as used in Persia for decorative purposes.

gate A passageway through a fence, wall, or other barrier, which slides, lowers, or swings open or shut.

gate contact See car door contact.

gatehouse A building, enclosing or accompanying a gateway for a castle, manor house, or similar buildings of importance.

gate operator An electro-mechanical device which opens or closes a gate when a switch supplies it with voltage.

gate pier A brick, concrete, or stone gatepost.

gatepost A post, usually one of a pair, between which a gate swings or slides; see hanging post.

gate tower A tower containing a gate to a fortress. (See illustration p. 456.)

gate valve, full-way valve A flow control device consisting of a wedge-shaped gate which can be raised to allow full, unobstructed flow or can be lowered to restrict the flow passage; not intended for close fluid flow control nor for very tight shutoff. (See illustration p. 456.)

gateway 1. A passage through a fence or wall. 2. A frame, arch, etc., in which a gate is hung. 3. A structure at an entrance or gate designed for ornament or defense.

gather See fullness.

gathering A transition between two sections (as in a chimney, flue, or duct) which have different areas.

gauge box Same as batch box.

gauge, gage 1. The thickness of sheet metal or metal tubing, usually designated by a number. 2. The diameter of wire or a screw, usually designated by a number. 3. The distance between two points, such as parallel lines of connectors. 4. A strip of metal or wood used as a guide to control the thickness of a bituminous or concrete paving; called a screed when used in plastering. 5. A measuring instrument, esp. one for measuring liquid level, dimensions, or pressure. 6. See mortise gauge. 7. In roofing, the length of a shingle, slate, or tile that is exposed when laid. 8. The quantity of gauging plaster used with common plaster (lime putty) to hasten its setting, etc. 9. To mix gauging plaster with lime putty, to effect better control of the set, to prevent shrinkage of the lime putty, and to increase its strength. 10. To cut, chip, or rub stone or brick to a uniform size or shape.

gauge board 1. Same as gauging board. 2. A pitch board.

gauged Descriptive of a material which has been ground so that various pieces are of the same thickness or of a desired shape.

gauged arch An arch of wedge-shaped bricks which have been shaped so that the joints radiate from a common center.

gauged brick 1. A brick of special shape that has been cut with a chisel or saw and then ground (for example, on coursed sandstone) to accurate dimensions. 2. A tapered arch brick.

gauged mortar Mortar consisting of a mixture of cement, lime, and sand in specified proportions.

gauged skim coat In plastering, a very thin final coat of gauging plaster and lime putty, troweled to a smooth, hard finish.

gauged stuff A term occasionally used for lime plaster or for lime mortar.

gauged work 1. A precise brickwork in which bricks are cut or sawn to shape and then rubbed to an exact size and smooth finish. 2. Plastering, such as the application of moldings or ornaments, which is done with gauged plaster.

gauge glass A device which indicates the level of a liquid in a tank, vessel, or the like.

gauge pile See guide pile.

gauge pressure The pressure, of a gas or liquid, minus the value of atmospheric pressure.

gauge rod A measuring stick for checking the accuracy of the gauge in brickwork; called a story rod if used to mark floor and sill levels.

gauge stick See scantle.

gauging The addition of a measured quantity of material to lime mortar in order to modify its properties.

gauging board A board on which cement, mortar, or plaster is mixed.

gauging box A batch box.

gauging plaster A special gypsum plaster mixed with lime putty; used as a finish coat.

gaul A hollow spot or area in a coat of plaster, mortar, or the like.

gault brick A brick made from a mixture of a heavy thick clay soil and sand that produces a color of brick between white and pale yellow, depending on the percentage of clay.

gauze 1. Any thin, open-weave, woven fabric; usually transparent. 2. A fine wire cloth; also called lawn.

gazebo A small ornamental structure, such as a pavilion, often providing a splendid view; usually built in a garden, in a park, or along a stream; same as belvedere or summerhouse.

gazophylacium A place where precious items were deposited, as a treasury in a palace or in a church.

GB Abbr. for glass block.

GC Abbr. for “General Contractor.”

G-cramp A large C-clamp, used by joiners.

geison A projection from the face of a wall such as from a cornice or coping.

gel A semisolid material, somewhat elastic, composed of matter in a colloidal state that does not dissolve; remains suspended in a solvent. Also see cement gel.

gelatin mold A semirigid mold made from gelatin; used in making plaster casts.

gel coat A thin, outer layer of resin, sometimes containing pigment, applied to a reinforced plastic molding to improve its appearance.

gelling Any process whereby paint or varnish thickens to jelly-like consistency. Also see livering.

gemel, chymol, gimmer, gymmer, jimmer Two corresponding elements of construction considered as a pair.

gemel window A window built into a pair of openings; a window having two bays.

geminated Coupled, as in coupled columns.

general bid A bid by a person seeking to become the contractor or general contractor on a project, as opposed to someone seeking to become a subcontractor.

general conditions That part of the contract documents (of the contract for construction) which sets forth many of the rights, responsibilities, and relationships of the parties involved. Also see conditions of the contract.

general contract 1. Under the single contract system, the contract between the owner and the contractor for construction of the entire work, 1. 2. Under the separate contract system, that contract between the owner and a contractor for construction of architectural and structural work.

general contractor The prime contractor who is responsible for most of the work at the construction site, including that performed by the subcontractors.

general diffuse lighting Lighting from luminaires which distribute 40% to 60% of the emitted light upward and the balance downward.

General Grant style A term occasionally used in the United States for the Second Empire style of architecture because of the number of public buildings in this style erected when he was president of the United States (1869–1877).

general hospital An institution, consisting of a building or buildings, in which patients, irrespective of sex and age, receive diagnostic and therapeutic medical and surgical services for most forms of illness, injury, or disability.

general industrial occupancy The use of a building of conventional design for all types of manufacturing operations, except high-hazard.

general lighting Lighting designed to provide a substantially uniform level of illumination throughout an area.

generally accepted standard A specification, code, rule, guide, or procedure in the field of construction, or related thereto, recognized and accepted as authoritative.

general requirements The title of Division 1 of the AIA’s uniform system for construction specifications, data filing, and cost accounting.

generator A machine that converts mechanical power into electric power.

generator set A unit consisting of an electric generator driven by an engine.

genets In Early English style architecture, cusps in the arch of a doorway.

gentrification The upgrading of urban property in a deteriorated area, usually resulting in the dispersal of the current residents and their replacement by a more affluent population.

geodesic dome A structure consisting of a multiplicity of similar, light, straight-line elements (usually in tension) which form a grid in the shape of a dome.

geodetic survey A land survey in which the curvature of the earth is considered; applicable for large areas and long lines; used for the precise location of basic points suitable for controlling other surveys.

geometrical stair A stair constructed around a stairwell without the use of newels at the angles or turning points.

Geometric style The early development of the Decorated style of English Gothic architecture, in the first half of the 14th cent., characterized by the geometrical forms of its window tracery.

geometric tracery Gothic openwork in the form of simple geometrical patterns, principally circles and multifoils.

Georgian arch Same as camber arch.

Georgian glass See wire glass.

Georgian plan A floor plan of a Georgian-style house; often two rooms deep, one on each side of a central hall, with a kitchen added at the rear of the house. The chimneys are usually located in the walls on each side of the house.

Georgian Revival See Colonial Revival.

Georgian style In Great Britain, the term “Georgian” is usually applied to the prevailing architectural style during the reigns of George I through George IV, from 1714 to 1830; derived from classical, Renaissance, and Baroque forms. In America, it is applied to a similar architectural style that emerged about 1700 and flourished until about 1780. Georgian architecture is often characterized by a rectangular plan, often with symmetrical wings flanking each side; a symmetrical brick or stone façade; pedimented gable; projecting central pavilion or a portico often with two-story columns; monumental pilasters extended the full height of the façade; a belt course; a slate-shingled hipped roof (often truncated and enclosed with a balustrade); a decorated classical cornice; five-ranked rectangular double-hung windows; lintels above rectangular windows; front windows on the ground floor, often pedimented; frequently a Palladian window; an elaborate front entrance; either a single door or a double door, with multiple panels in each leaf; often decoratively crowned; a pediment over the door; often, a projecting hood above the door; a fanlight or transom light above the door, often with sidelights on each side of it; decorative pilasters or engaged columns flanking the doorway. In elegant homes, the front door opened into a spacious entrance hall.

The introduction of the Georgian style in America varied with geographical region. In New England, two-story timber-framed houses with central chimneys predominated. In the South, brick and stone construction were widely used, with fireplace chimneys at the ends of the house; in large houses, a raised basement was common. Although initially relatively unpretentious, Georgian-style homes became larger, wider, and more elaborate over time. An arbitrary distinction is sometimes made by some architectural historians between Early Georgian and Late Georgian, considering the year 1750 as the approximate time of transition. However, the changes occurred gradually and at different times in different colonies.

geotechnical investigation A soil boring and sampling process (together with associated laboratory testing) required to establish the subsurface profiles and relative strengths of the strata encountered at depths likely to have an influence on the design of a building project. Also called a subsurface investigation.

German barn, Swiss barn Any one of a variety of barns, often serving as a combination barn and home, built during the 18th and 19th centuries by German-speaking immigrants to the New World; especially characterized by a shingled gambrel roof or gable roof; a second floor overhanging one side of the barn, well beyond the foundation; usually an inclined driveway providing direct entry to the threshing floor where wheat was threshed, hay was stored, and where the family lived. The basement was used as a stable for horses, cattle, and sheep; often of stone construction or masonry up to the threshing floor and wood construction above. Many stone barns had long, narrow, vertical slots in the walls for supplying the barn with fresh air. Also see bank barn, forebay barn, grundscheier, Pennsylvania barn, Sweitzer barn, slit ventilator.

German Colonial architecture Architecture attributed to German-speaking immigrants to America primarily in the years from about 1680 to 1780. Many of these early settlers first built a log house of hewn square timbers as a temporary home until they could construct more substantial housing. Common characteristics of their permanent houses included: a symmetrical façade, thick stone walls, a steeply pitched end-gabled roof usually covered with wood shingles or clay tiles; an attic story with windows at the gable ends and shed dormers on the roof, a porch at the gable end of the house or at the front of the house; small casement windows with battened shutters, later replaced by double-hung windows. If it was built into a hillside, it was called a bank house. Also see fachwerk, grundscheier, Pennsylvania Dutch, rauchkammer, springhouse.

German siding Drop siding with a concave upper edge which fits into a corresponding groove in the siding above.

gesso A mixture of gypsum plaster, glue, and whiting; applied as a base coat for decorative painting.

geyser An instantaneous-type water heater.

GFCI Abbr. for ground fault circuit interrupter.

ghost trap Same as grave trap.

GI On drawings, abbr. for galvanized iron.

giant arbor vitae Same as thuya.

giant order See colossal order.

giant pilaster Same as colossal pilaster.

gib 1. A steel strap used to clasp two members together. 2. Same as gib or jib door.

gib-and-cotter joint A joint in timber construction, formed with a steel strap tightly drawn in position by steel clips and wedges.

Gibbs surround The framing of a door or window by a head composed of a (usually triple) keystone and by jambs that are bordered by protruding rectangular blocks of stone.

gib door See jib door.

giglio A Florentine emblem such as a fleur-de-lys.

gig stick A radius rod.

gild See guildhall.

gilding 1. Gold leaf, gold flakes, brass, etc., applied as a surface finish. 2. The surface so produced.

gilding metal An alloy containing nominally 95% copper and 5% zinc. Generally available as flat products, rod, and wire.

gilloche See guilloche.

Gilmore needle A device used for determining the setting time of hydraulic cement.

gilsonite, uintahite A naturally occurring grade of asphalt used in floor tile, paints, paving, and roofing.

gimlet A small tool with a pointed screw at one end; used to bore small holes in wood by turning it with one hand.

gimmer Same as gemel.

gin block A simple form of tackle block with a single wheel, over which a rope runs.

gingerbread Highly decorative, elaborate woodwork, usually turned on a lathe and/or fashioned on a jigsaw.

Gingerbread folk architecture A style of folk architecture widely applied to homes in America from about 1870 to 1910; especially characterized by the heavy use of gingerbread, spindlework, and ornate bargeboards. Often, these elaborate embellishments were added to an older house to update it or included in a new house to make it appear to be au courant. Heavily ornamented porches were common; in larger houses, many were two stories high, with decorative balustrades with spindlework balusters and lacelike spandrels. Also see Carpenter Gothic, Queen Anne style, Steamboat Gothic, Victorian architecture.

Gingerbread style A richly decorated American building fashion of the 19th cent.

girandole A branched light holder, either standing on a base or projecting from a wall.

girder A large or principal beam of steel, reinforced concrete, or timber; used to support concentrated loads at isolated points along its length. (See illustration p. 462.)

girder bracket Same as trimming joist.

girder casing The material which totally encloses a girder, as one that projects below a ceiling.

girder post Any column or post which supports a girder.

girding beam See side girt and end girt.

girdle A band, usually horizontal; esp. one ringing the shaft of a column.

girdle cornice A cornice that encircles a building like a girdle.

girt A horizontal structural member in the framing, 3 of an early timber-framed house, typically supporting the ends of the ceiling joists and acting as the main horizontal support for the floor above; often located about halfway between the groundsill, 2 and the horizontal timber at the top of the wall (the top plate) The term girt often is preceded by an adjective indicating its position; for example, front girt denotes a heavy timber that runs horizontally along the front of the house; rear girt denotes a heavy timber that runs horizontally along the rear face of the house; chimney girt denotes a heavy timber that acts a main horizontal support between chimney posts. See illustration under timber-framed house.

girt board A timber girt.

girt strip Same as ledger board.

GL On drawings, abbr. for glass.

glacial till See till.

glacis A sloped embankment in front of a fortification, so raised as to bring an advancing enemy into the most direct line of fire.

gland joint In hot water piping, a joint that permits movement resulting from thermal expansion or contraction.

gland seal A seal used to prevent leakage between a fixed part and a movable part.

glare The sensation produced by brightnesses within the visual field that are sufficiently greater than the luminance to which the eyes are adapted to cause annoyance, discomfort, or loss in visual performance and visibility.

glass A hard, brittle inorganic substance, ordinarily transparent or translucent, produced by melting a mixture of silicates (such as sand) and a flux (such as lime and soda). Molten glass may be blown, cast, drawn, rolled, or pressed in a variety of shapes. Centuries ago, window glass was thin, generally of poor quality, often green or violet in hue, streaked with air bubbles. After about 1700, the manufacturing processes improved significantly so that the price of glass dropped significantly, the sizes of panes increased, and the use of window glass became more widespread. Also see annealed glass, art glass, broad glass, crown glass, cylinder glass, figured glass, float glass, ground glass, insulating glass, iridescent glass, jealous glass, laminated glass, leaded glass, muff glass, opalescent glass, organic-coated glass, painted glass, plate glass, processed glass, rolled glass, sheet glass, solar glass, stained glass, tempered glass, Tiffany glass, tinted glass, toughened glass, wire glass.

glass block, glass brick A hollow block of glass, usually translucent with textured faces; has relatively low thermal-insulation and low fire-resistance value; used in non-load-bearing walls.

glass bulb sprinkler In a fire protection system, a sprinkler which opens under the influence of heat by the breakage of a glass bulb; the bulb breaks as a result of the pressure exerted by the expansion of the liquid which it contains.

glass cement Any binding material used to cement glass to another piece of glass or other material.

glass cloth A closely-woven cloth fabricated of glass fibers; often used as a finishing jacket over thermal insulation for piping.

glass concrete A concrete slab or panel in which individual translucent glass lenses have been set, usually in a geometric pattern, to permit passage of light.

glass cutter A hand tool used for scoring or cutting glass; consists of a small, sharp wheel of hardened steel which is set in a handle, or a tool with a diamond point.

glass door A door of thick, heat-strengthened or tempered glass; there are no rails or stiles.

glass fiber, glass fibre See fiberglass.

glass house 1. British term for greenhouse. 2. A residence having exterior walls which are almost completely glass; an outstanding example is Philip Johnson’s glass house in Connecticut.

glass paper A type of fine sandpaper, made with powdered glass as the abrasive.

glass pipe A pipe fabricated from a low-expansion borosilicate glass having a low alkali content; used primarily for the drainage of various corrosive liquids; very brittle and therefore used only where protection is provided against mechanical damage to the pipe.

glass reinforced concrete Concrete that has been reinforced by the addition of glass fibers to the concrete mix.

glass seam A fracture in limestone that has been recemented and annealed by deposition of transparent calcite; limestone containing such a seam is structurally sound.

glass silk Same as glass wool.

glass size The size of a piece of glass required for glazing a given opening, allowing suitable clearance between the edge of the glass and the rebate.

glass slate Same as glass tile.

glass stop 1. A glazing bead. 2. A fitting which holds the lower end of a patent glazing bar; prevents the pane from sliding down.

glass surface coating 1. A coating applied to a glass surface, usually to tint the glass a desired color or to control the amount of solar radiation that is transmitted through the glass. The coating may be applied as the molten glass passes along a long continuous oven; alternatively, the coating may result from dipping the glass into a chemical solution, and then drying and firing it. 2. A metal coating evaporated on a surface while it is under a vacuum.

glass tile, glass slate Tile fabricated of translucent or transparent glass; installed in a roof surface to allow light to enter the room below.

glass wool, glass silk Spun glass fibers in bulk form; resembles wool; used as thermal insulation, in air filters, and in fabricating fiberglass blankets, boards, and tile. Also see mineral wool, fiberglass.

glaze 1. A ceramic coating, usually thin, glossy, and glass-like, formed on the surface of pottery, earthenware, etc. 2. The material from which the ceramic coating is made. 3. To install glass in windows, doors, storefronts, curtain walls, and various other segments of building construction.

glaze coat 1. In built-up roofing having a smooth surface, the top layer of asphalt. 2. A temporary coating of bitumen used to protect the plies of built-up roofing when the application of the top pouring and surfacing is delayed. 3. A layer of thin, almost transparent, colored paint which allows an undercoat to show through.

glazed 1. Said of an opening that is filled with sheets of glass, as in a window. 2. Said of a finish that is composed of ceramic materials fused into its surface, usually making it essentially impervious to moisture.

glazed block A concrete block that has been glazed on one side, thereby providing the side with a smooth, hard surface; often colored.

glazed brick A brick that has been fired in a kiln hot enough to fuse the clay and sand on its surface, usually forming a dark glassy coating.

glazed door 1. Any door that has top and bottom rails and is glazed. 2. A French door.

glazed interior tile A glazed ceramic tile having a body that is suitable for interior use, usually nonvitreous; not fabricated for use under conditions of excessive impact or of freezing and thawing.

glazed tile Ceramic tile having a fused impervious glazed surface finish (clear, white, or colored) composed of ceramic materials fused into the body of the tile; the body may be nonvitreous, semivitreous, or impervious.

glazed work Brickwork built with enameled brick or glazed brick.

glazement A waterproof surfacing applied on a masonry surface.

glazier’s chisel A putty knife shaped like a chisel, used in setting glass.

glazier’s point, sprig A thin small three- or four-cornered piece of sheet metal, used to hold a pane of glass in a window frame while putty is applied.

glazier’s putty A type of glazing compound. Also see putty.

glazing 1. Setting glass in an opening. 2. The glass surface of a glazed opening.

glazing bar One of the vertical or horizontal bars within a window frame which hold the panes of glass; a muntin.

glazing bead, glass stop 1. Same as bead, 3. 2. At a glazed opening, removable trim that holds the glass firmly in place.

glazing block Same as setting block.

glazing brad Same as glazier’s point.

glazing clip A metal clip used to retain a pane of glass in a metal frame while glazing compound is applied.

glazing color A transparent wash, used to cover a ground coat of paint.

glazing compound A putty-like material used to seal window glass in place; differs from putty, 1 in that it retains its plasticity for an extended period of time.

glazing fillet A small strip of wood used to hold glass in a rebate; a glass stop.

glazing gasket A prefabricated strip of material used to seal and secure glass, or sealed glazing units, into frames and openings by a dry glazing method without using compounds or tapes.

glazing molding 1. A molding which serves as a glazing fillet. 2. A glass stop, 2.

glazing point Same as glazier’s point.

glazing rabbet, glazing rebate A rabbet, 3 that receives the glass in a window frame or glazing bar.

glazing size See glass size.

glazing spacer block One of a number of blocks used to support glass in its frame.

glazing sprig, glazing brad A headless nail used as a glazier’s point to retain a pane of glass in a wooden opening while the putty is soft.

glazing stop Same as glass stop.

glazing tape A ribbon of resilient material for sealing a glass pane or panes in a frame, sash, or opening.

glebe house An archaic term for parsonage.

gliding window Same as sliding sash.

global illuminance The sum of light from all natural sources: direct, the sky, and ground-reflected.

globe, light globe 1. A transparent or diffusing enclosure (usually of glass) to protect a light source, to diffuse and redirect the light, or to change the color of the light. 2. An incandescent lamp.

globe valve A valve in which the flow of water is controlled by a movable spindle which lowers to a fixed seat, thereby restricting the flow through the valve opening; the spindle is fitted with a washer to provide tight closure; usually enclosed in a chamber having a globular shape.

glory The luminous halo encircling the head of a sacred person and the radiance or luminous emanation encompassing the whole.

gloss The degree of surface luster; ranges from a matte surface practically without sheen to an almost mirror-like glossy finish; intermediate conditions (in increasing order of glossiness) are: flat, eggshell, semigloss, and full gloss or high gloss.

glossing up The appearance of glossy areas in a matte surface when it is fingered or rubbed. Also see burnishing.

glossy paint A paint that dries with a superficial shine or luster, in contrast to a flat paint.

glow discharge An electric discharge in a gas at low pressure which produces a diffuse glow; characterized by a low cathode temperature, a low current density, and a high voltage drop.

glow lamp A glow discharge lamp which generates light in an ionized gas close to the electrodes; commonly used as an indicating device because of the low power consumption.

glue Any fluid adhesive substance used for joining materials, often of substantial weight; generally refers to adhesives that cure without heat: animal glue, fish glue, emulsion glue, etc.

glue block, angle block A block of wood, set into an interior angle formed by two boards, and glued in place to strengthen the joint.

glue down As applied to carpet, the installation of the carpet backing by adhering it directly to the flooring with an adhesive.

glued-laminated timber A manufactured product consisting of four or more wood layers, none of which exceeds 2 in. (5 cm) in thickness, bonded together with adhesive; may be comprised of pieces which are end-joined to form any desired length, or which may be glued edge-to-edge to give greater width.

glued-up stock Pieces of wood (including veneer or furniture) joined together by gluing.

glue line The line of adhesive between two surfaces that are glued, as between plies in plywood.

glycerol, glycerin, glycerine Colorless, odorless fluid used in mixing synthetic and natural resins for paints and varnishes; used for making distempers more pliable; used in the manufacture of some adhesives.

glyph 1. A V-shaped, vertically oriented groove used as an ornament in the Classical Revival style and its derivatives; usually found on a Doric frieze, as in triglyph. 2. A sculptured pictograph.

glyptic Pertaining to carving or engraving.

glyptotheca A sculpture gallery.

GM Abbr. for “grade marked.”

gneiss A coarse-grained metamorphic rock having discontinuous foliation; usually dark; composed mainly of quartz, feldspar, mica, and ferromagnesian minerals. Generally classed as trade granite in the building stone industry.

goblet pulpit In a church, a pulpit on a central support that is often hexagonal or circular in section, similar to a goblet.

go-devil A device used to clean a pipeline by placing it at the pump end of the pipeline and forcing it through the pipe by water pressure.

godown In India and the Far East, a storehouse of any description.

godroon See gadroon.

going (Brit.) 1. The horizontal distance between two consecutive risers of a step. 2. Of a stair or flight, the horizontal distance between the first and last risers, i.e., the run.

going rod A rod used in laying out the going, 1 of a flight of steps.

gold bronze A powdered copper alloy used in the manufacture of gold or bronze paint; usually contains copper, zinc, lead, and tin.

golden section The division of a line into two segments so that the ratio of the whole line to the larger segment equals the ratio of larger segment to the smaller one; often called the golden section. This ratio was once considered by some as having an inherent aesthetic value.

gold foil See gold leaf.

gold leaf Very thin sheets of beaten or rolled gold, used for gilding and inscribing on glass; usually contains a very small percentage of copper and silver. Sometimes heavy gold leaf is classified as gold foil.

gold size A varnish used to attach gold leaf or foil to a surface; it turns sticky quickly on application, and then sets slowly.

golosniki In early Russian architecture, acoustic resonators, made of clay, which were set into the upper portions of the walls of some churches; the mouth of the resonator faced the interior of the church and was flush with the wall surface. Similar resonators have been found in some Greek Orthodox and early Scandinavian churches.

gonge The Anglo-Saxon term for a privy.

gont A thin wood shingle, used for roofing in early Russian architecture.

good morning stairs In a full Cape house, the front stairs leading from the front hall to the attic rooms; at the chimney block, the stairs turn both right and left, serving both sides of the house.

goods lift In Britain, a service elevator.

goose neck 1. Any section of pipe, curved like the neck of a goose, or in a U-shape; sometimes flexible. 2. In ductwork, an inverted U-shaped duct section with a screened opening; used for air intake or exhaust. 3. A curved section of a handrail which forms its termination at the top of a newel post.

gopuram In Hindu architecture, a tall monumental gateway.

gore Same as lune.

gore lot A small triangular lot.

gorge 1. In some orders of columnar architecture, a narrow band around the shaft near the top, or forming part of the capital near the bottom; a fillet or narrow member which seems to divide the capital from the shaft. 2. A cavetto or hollow molding. 3. A narrow entry into a bastion.

gorge cornice Same as Egyptian gorge.

gorgerin See hypotrachelium.

gorgoneion In classical decoration, the mask of a Gorgon, a woman with snakes for hair, to avert evil influences.

gospel hall House for Protestant Christian worship.

gospel side The left side of a church as one faces the altar.

Gothic arch A loose term often denoting any arch with a point at its apex, such as a lancet arch.

Gothic architecture The architectural style of the High Middle Ages in Western Europe, which emerged from Romanesque and Byzantine forms in France during the later 12th cent. Its great works are cathedrals, characterized by the pointed arch, the rib vault, the development of the exterior flying buttress, and the gradual reduction of the walls to a system of richly decorated fenestration. Gothic architecture lasted until the 16th cent., when it was succeeded by the classical forms of the Renaissance. In France and Germany one speaks of the Early, High, and Late Gothic; the French middle phase is referred to as Rayonnant, the late phase as Flamboyant. In English architecture the usual divisions are Early English, Decorated, and Perpendicular.

Gothick See Neo-Gothic.

Gothic Revival A movement originating in the 18th century and culminating in the 19th century, flourishing throughout Europe and the United States, aimed at reviving the spirit and forms of Gothic forms; applied to country cottages, churches, some public buildings, and castlelike structures. Gothic Revival buildings usually are characterized by ashlar masonry, polychromed brickwork, or wood walls, often extending into the gables without interruption; Gothic motifs such as battlements, decorative brackets, finials, foils, foliated ornaments, hood moldings, label moldings, pinnacles, pointed arches, towers, turrets; often, a porch with flattened Gothic or Tudor arches; a symmetrical façade; steeply pitched gables often decorated with ornate gingerbread bargeboards; projecting eaves; decorative slate or shingle patterns on the roof; occasionally, a flat roof with crenelated and castellated parapets; ornamental chimney stacks and chimney pots; a cast-iron decorative strip at the ridge of the roof; windows extending into the gables; often, an elaborately paneled front door set into a lancet arch; the entry door sometimes within a recessed porch or under a door hood, occasionally bordered with sidelights. The initial phase is sometimes called Early Gothic Revival; the latter phase is sometimes called Late Gothic Revival or Victorian Gothic. Also see Collegiate Gothic, High Victorian Gothic, and Carpenter Gothic.

Gothic sash A term occasionally applied to a lancet window.

Gothic survival The survival of Gothic forms and construction techniques long after the demise of Gothic architecture (for example, as late as the 17th century); usually in a provincial context, as distinct from Gothic Revival.

gouache 1. A method of painting, using opaque pigments pulverized in water and mixed with gum. 2. A painting so made. 3. An opaque color used in the process.

gouge 1. A chisel with a longitudinal curved blade, used to cut holes, channels, or grooves in wood or stone. 2. A form of wear in resilient floor coverings which is accompanied by removal of material and penetration considerably below the immediate floor surface.

gouge bit A bit shaped like a gouge, with the piercing end sharpened to a semicircular edge for shearing the fibers around the margin of the hole; removes the wood almost as a solid core.

gouge slip, oilstone slip, slipstone A shaped oilstone for sharpening gouges or shaped chisels.

gouge work An ornamental wood surface having decorative surface marks made with a chisel whose blade is curved.

government anchor A type of steel anchor which is inserted through a hole in the web of a steel beam; used to anchor a wall-bearing beam to masonry construction.

government house 1. Building for the offices of the main departments of government, esp. in English colonies or Commonwealth nations. 2. Governor’s state home, esp. in a Crown colony.

GOVT On drawings, abbr. for “government.”

gpd Abbr. for “gallons per day.”

gpm Abbr. for “gallons per minute.”

gps Abbr. for “gallons per second.”

GR On drawings, abbr. for “grade.”

grab bar A hand grip, usually installed in a shower, which may be used for steadying oneself.

grab bucket A clamshell.

grab crane A crane which is fitted with a clamshell.

grab rail Same as grab bar.

grab set See flash set.

gradation See particle-size distribution.

grade 1. The classification of materials by quality. In lumber, plywood, and building boards, the classification usually depends on the quality for one face only. 2. The ground elevation or level, contemplated or existing, at the outside walls of a building, or elsewhere on the building site. 3. Rate of rise or fall of a roadway, often expressed in feet per 100 ft, in meters per kilometer, or as a percentage, ascending grades being plus, descending minus. 4. The slope of a line of pipe with reference to the horizontal; usually expressed as the fall in a fraction of an inch per foot (or centimeters per meter) length of pipe. 5. The cut-off elevation of a pile.

grade beam That part of a foundation system (usually in a building without a basement) which supports the exterior wall of the superstructure; commonly designed as a beam which bears directly on the column footings, or may be self-supporting, as a long strap footing.

grade correction A correction applied to a distance measured on a slope to reduce it to a horizontal distance between the vertical lines through its end points.

grade course The first course at grade level, usually waterproofed with a damp check or damp course.

graded aggregate Aggregate having a particle-size distribution characterized by uniform grading.

graded sand Fine aggregate (diameter under ¼ in., i.e., 6.4 mm) having a particle-size distribution characterized by uniform grading.

graded standard sand Ottawa sand, accurately graded between the 600-µ (US Standard No. 30) and 150-µ (No. 100) sieves; used in the testing of cements. Also see Ottawa sand, standard sand.

grade hallway An enclosed passageway that provides a protected path of escape in the event of fire; terminates at a street or an open space or court communicating with a street.

grade level The level of the surface of the ground after the cut and fill process has been completed.

grade line A line usually marked with stakes or monuments, each having an elevation referred to a common datum; by measurement or computation from such elevations and stakes, a grade is established between the terminal points.

grade passageway Same as grade hallway.

grade plane A reference plane representing the average of the ground level adjoining a building at its exterior walls.

grader, towed grader A multipurpose machine used for leveling and crowning, mixing and spreading, ditching and bank sloping, and side casting material, or for light stripping operations; not intended for heavy excavation.

grade ring A precast concrete ring at the top of a manhole; used to adjust the top of the manhole so that it is set at the proper angle.

grade school See elementary school.

grade slab A reinforced concrete slab, set directly on the ground, which serves as the foundation for the structure above.

grade stake In earthwork, a stake marking the specified level.

grade strip A strip of wood which is nailed to the inside of a concrete form to indicate the upper line to which concrete is to be poured.

gradetto Same as annulet.

gradient 1. The degree of inclination of a surface, road, or pipe, often expressed as a percentage. 2. A rate of change in a variable quantity, as temperature or pressure. 3. A curve representing such a rate of change.

gradienter An attachment to an engineer’s transit with which an angle of inclination is measured in terms of the tangent of the angle, rather than in degrees and minutes.

gradinata The steps in a Classical amphitheater.

gradine 1. A step. 2. A raised shelf above and at the back of an altar.

grading 1. The action of excavating or filling, or a combination thereof. 2. See particle-size distribution.

grading curve A graphical representation of the proportions of different particle sizes in a material; obtained by plotting the cumulative or separate percentages of the material passing through sieves in which the aperture sizes form a given series.

grading plan A plan which shows the proposed finish of the ground surface of a given site, usually by means of contours and grade elevations.

grading rules Specifications by which lumber, plywood, etc., are grouped according to quality.

grading timber The sorting of timber, logs, or lumber according to the number and type of defects.

graduated course One of a number of courses of roofing slates that diminish in gauge from the eaves to the ridge.

graecostasis In the Roman Forum, a platform where the ambassadors from foreign states stood to hear debates and attend ceremonies.

graffito Casual remark or depiction drawn on a wall; not synonymous with sgraffito.

graft To join a scion, shoot, or bud to the stock of another similar plant.

grain 1. The direction, arrangement, or appearance of the fibers in wood, or the strata in stone, slate, etc. 2. The easiest cleavage direction in a stone. 3. Any small, hard particle, as of sand. 4. A unit of weight measure in the English system of units; 7,000 grains equals 1 lb; used as a measure of the weight of moisture in air.

graining Simulating a grain such as wood or marble on a painted surface by applying a translucent stain, then working it into suitable patterns with tools such as graining combs, brushes, and rags. See false woodgraining, faux bois, woodgraining.

grain size A measure of the size of mineral particles of soil or rock; a physical characteristic of the particles of a soil which affects its mechanical properties; used in classification and identification.

grain slope The angle of grain in a piece of lumber relative to a line parallel to its length. The angle for structural timber (as for beams) is restricted to a slant of 1 part in 8.

granary A storehouse for grain, usually after it has been threshed, or for the storage of corn after it has been husked.

grandmaster key A key that operates locks in several groups, each of which has its own master key.

grandstand A structure, often with a roof, which supports standing or seated spectators at a racecourse, ball field, stadium, or similar public places.

grand tier The tier immediately above the parterre in an opera house, theater, etc.

grange 1. A farm. 2. A farmhouse and its outbuildings.

granite 1. An igneous rock having crystals or grains of visible size; consists mainly of quartz, feldspar, and mica or other colored minerals. 2. In the building stone industry, a crystalline silicate rock having visible grains; this includes gneiss and igneous rocks that are not granite in the strict sense.

graniteware A one-coat porcelain-enameled article having a mottled pattern which is produced by the controlled corrosion of the metal base prior to firing.

granitic finish A finish provided by a face mix of granolithic concrete.

granolithic concrete Concrete suitable for use as a wearing surface finish for a floor; made of cement mixed with specially selected aggregate (originally granite chips) of suitable hardness, surface texture, and particle shape.

granolithic finish A surface layer of granolithic concrete which may be laid on a base of either fresh or hardened concrete.

granular-fill insulation A loose-fill thermal insulation, such as vermiculite or perlite, in the form of granules, pellets, nodules, powder, or flakes; can be poured or placed by hand without mechanical means. Also see loose-fill insulation.

granular material Gravels, sands, or silts which exhibit no characteristics of cohesiveness or plasticity; more permeable than cohesive or plastic soils.

granular soil Soil comprised of sediments or other unconsolidated accumulations of particles (such as gravel, sand, or silt) having no clay content; crumbles easily when dry.

granulated blast-furnace slag The nonmetallic product consisting essentially of silicates and aluminosilicates of calcium which is developed simultaneously with iron in a blast furnace and is granulated by quenching the molten material in water or in water, steam, and air. Also see blast-furnace slag.

granulated cork Small particles of cork used as loose-fill thermal insulation, to make cork tile, etc.

grapevine joint See scribed joint, 2.

grapevine ornament A running ornament usually consisting of a grapevine with bunches of grapes and grape leaves.

graphics The art of drawing, esp. of drawing according to mathematical rules, as in perspective, projection, etc., associated with architectural and engineering plans.

graphite, plumbago One of the forms under which carbon occurs in nature; electrically conductive; in powdered form, used as a lubricant.

graphite paint A painting compound consisting of powdered graphite and oil; used to coat metallic structures to inhibit corrosion.

grapple A clamshell, 2 which has three or more jaws; especially suitable for handling rocks such as rip rap.

grappler A pointed spike that is driven into masonry to provide an eye for support of the brackets of a scaffold.

grass cloth, China grass cloth A loosely woven fabric of vegetable fibers; used for wall covering.

grass house Any primitive house built of natural materials such as grass, reeds, or fronds; usually having a round or rectangular shape and a thatched roof; examples include palma hut and a Hawaiian hale.

grass table Same as ground table.

grassed waterway A grass-surfaced channel for water, usually used to carry away surface runoff and reduce surface erosion.

grate A surface with suitable openings to support a fuel bed, such as coal, and permit passage of air through the burning fuel. Designed to permit removal of unburned residue, and may be horizontal or inclined, stationary or movable.

grating 1. A grate; also see coke grating. 2. A grille. 3. Same as grillage. 4. See bar-type grating. 5. See plank-type grating.

gravel A coarse granular aggregate, larger than sand; formed either naturally or by crushing rock; will pass a 76.1-mm (3-in.) sieve and be retained on a 4.76-mm (No. 4) sieve.

gravel board, gravel plank A board attached near the lower edge of a wood fencing so that the fencing does not touch the ground; prevents the lower end of the fencing from rotting.

graveling-in The spreading of gravel on top of a flood coat, 2 in built-up roofing.

gravel plank See gravel board.

gravel roofing See built-up roofing.

gravel stop, gravel strip, slag strip A flange, usually of a metal strip, used to prevent gravel or loose surfacing from washing off a roof; may also provide a finished edge for built-up roofing.

grave trap On a theater stage, an oblong trap, 2 often located toward the front of the stage along its center line.

gravitational water Same as free water, 2.

gravity convection The transfer of heat resulting from differences in density of air or water (because of differences in temperature), that thereby causes the flow of air or water.

gravity drainage system See building gravity drainage system.

gravity feed Said of a chute that transports waste materials, soiled linen, etc., from one level of a building to another by the force of gravity.

gravity flow The flow of water drawn through a conduit under the force of gravity.

gravity hinge A hinge that closes automatically as a result of the weight of a door to which it is attached.

gravity main See building gravity drainage system.

gravity supply, gravity water system A water system in which the source of water is at a higher elevation than the place where the water is to be used. (See illustration p. 472.)

gravity-type refuse chute A refuse chute in which waste material is conveyed down the chute by the force of gravity. (See illustration p. 472.)

gravity wall A massive concrete wall that nation resists overturning by virtue of its own weight.

gravity water system See gravity supply.

gravity water tank, gravity tank A water storage tank in which water is stored at atmospheric pressure and distributed by gravity flow in a downfeed system; the tank is usually elevated above the roof of a building and is filled by a house pump.

gravel roofing See built-up roofing.

gray cast-iron pipe See cast-iron pipe.

gray scale A series of achromatic samples in discrete steps in lightness from white to black.

gray water Waste water which may be a combination of liquid and water-carried wastes, with the exception of human wastes.

grazing light Light that is reflected from a source placed close to a surface, usually to emphasize the texture of the surface.

gre See grees.

grease extractor Equipment which traps droplets of grease and greasy vapors from the exhaust air of cooking equipment.

grease interceptor See grease trap.

grease trap, grease interceptor A device for removing grease from waste water by allowing the retained liquid to cool and the grease to solidify; then the grease is separated by flotation; it rises to the top of the trap, where it is held.

great chamber A chamber within the great room of a manor house.

great house The main or central residence of an estate or plantation.

great room The main room of a house of some pretension; usually the room largest in size.

great tower See keep.

grece Same as grees.

Grecian style A 19th-century term for Greek Revival style.

Greek cross A cross with four equal arms.

Greek key See fret.

Greek masonry See isodomum.

Greek Revival style An architectural style based on the reuse of ancient Greek forms in architecture. Public buildings in this style were usually symmetrical in plan and rectangular in shape. Buildings in this style are commonly characterized by: asymmetrical plan, a symmetric front-gabled façade with a classical pedimented portico extending across the building; a façade of brick, clapboard, or stone construction; a partial-height porch, sometimes with the porch roof having a raked cornice supported on round or square columns with ornamental capitals; pilasters; a frieze or a plain wide band of trim with a simple architrave below a heavy cornice; walls that imitate flat stonework, wood buildings often painted white; typically sparse ornamentation, including classical Greek decorative motifs; gabled or hipped roof; widely spaced double-hung windows trimmed with decorative crowns; a wide, imposing entryway, framed by pilasters or engaged columns; an entry door usually having raised panels with a horizontal line of small lights above the door; a vertical line of small lights on each side of the door. In America, during the height of its widespread popularity from about 1820 to the 1850s, Greek Revival was frequently called the National Style. Also see Classical Revival style and Neoclassical style.

Greek theater An open-air theater constructed by the ancient Greeks; usually built on a hillside, with no outside facade. The orchestra, 1, on which the actors and chorus performed, was a full circle; behind it was the skene, a temporary or permanent building for the actors’ use. In the classic theater, the seating area (around and facing the orchestra) usually occupied approx. three-fifths of a circle. Also see Roman theater.

green 1. See green concrete. 2. See green lumber. 3. See green mortar. 4. See undercuring. 5. An open space or public park in the center of a town or village. 6. A bowling green or putting green.

green architecture Architecture in which the design is focused on making a building energy-efficient, so as to reduce its energy consumption, water consumption, operating costs, and environmental impact. Such efficiencies include the maximal use of natural lighting, low-e glass, solar electric systems, energy-efficient lighting systems, energy-efficient ventilation systems including the use of the chimney effect, and newer sustainable materials and techniques that minimize heat loss in buildings.

greenbelt A wide area of parks, farmland, or undeveloped land surrounding a community.

green concrete Concrete which has set but not appreciably hardened.

green glass A low-grade glass which is green because of impurities in its raw materials.

greenheart A British Guiana hardwood having high density and strength; difficult to machine; used for piles, planks, etc., where strength is important.

greenhouse, glasshouse A glass-enclosed, heated structure for growing plants and out-of-season fruits and vegetables under regulated, protected conditions. Also see conservatory, hothouse, orangery.

green lumber Lumber which has not been dried or seasoned.

green manure Green herbaceous plants plowed under to benefit the soil.

green mortar Mortar that has set but yet not dried.

green room A lounge near the stage of a theater or concert hall where actors or musicians may rest or receive visitors before or after a performance.

green timber Freshly converted timber that has not been dried in a kiln; has a high moisture content, usually well above 50%.

greensand A resin used to oxidize the soluble iron in water and then to filter it out.

greenstone A basic igneous rock having a green color due to iron-bearing silicate minerals; quarried and fabricated for structural and decorative dimension stone.

greensward Turf, green with grass, usually well-tended.

grees, gre, greese, gryse In medieval architecture, a step or flight of steps.

G/Rfg, G/R Abbr. for “grooved roofing.”

grid 1. See gridiron. 2. See grillage. 3. In surveying, closely-spaced reference lines which are perpendicular to each other; elevations usually are taken at the intersections of these lines.

grid bearing The angle in the plane of the projection between a line and a north-south grid line.

grid ceiling A ceiling with apertures through which natural or artificial light can pass.

grid foundation A combined footing which is formed by a number of intersecting continuous footings, loaded at their points of intersection; the area covered is less than 75% of the total area within the outer limits of the assembly.

gridiron A framework (usually of steel) over a theater stage and immediately below the stage-house roof; used as the structural support from which scenery and lighting equipment are hung. Also called a grid.

grid plan A city plan in which the streets are laid out in a rectangular pattern of lines forming rectangles of uniform size.

grid pulley, grid sheave A pulley, located on a gridiron, through which a cable or rope of a rigging system passes.

grid sheet system A system of soldier beams and horizontal sheeting used to brace the lateral face of a deep excavation or cut; the soldier beams receive lateral support from wales and braces.

grid system See exposed suspension system.

griffe See spur, 1.

griffin, griffon, gryphon A mythological beast having a lion’s body with an eagle’s head and wings; used decoratively.

grillage 1. A framework of heavy timbers, steel, or reinforced concrete beams laid longitudinally and crossed by similar members laid upon them to spread a heavy load over a larger area, esp. for use where the ground is not firm. 2. A series of steel beams, bolted together and placed over a footing; used to distribute a concentrated column load over the top of the footing.

grille 1. A grating or openwork barrier, usually of metal but sometimes of wood, stone, or reinforced concrete; used to cover, conceal, decorate, or protect an opening, as in a wall, floor, or outdoor paving. 2. A louvered or perforated covering for an air passage opening, which can be located in the wall, ceiling, or floor.

grillroom, Brit. grille room A room for informal dining in a restaurant, club, or hotel.

grillwork Material which functions as, or has the appearance of, a grille.

grinder pump A special type of solids-handling pump, designed to grind sewage solids into a fine slurry.

grindstone A rotating solid stone wheel (usually sandstone) used for grinding, shaping, sharpening, or polishing.

grinning through 1. The visible appearance of lathing through a plaster coat. 2. The visible appearance of an undercoat of paint through a topcoat.

grip 1. Of a mechanical fastener: the thickness of the material or parts which the fastener is designed to secure when assembled. 2. Of a rivet: the thickness of the plates or parts through which the rivet passes. 3. A channel that carries away rain water from a foundation, during its construction.

grip handrail A handrail having a diameter which is especially easy to grasp; often has a roll molding along its upper surface.

grip length See bond length, development length.

grisaille 1. A system of painting in grey tints of various shades; used either for decoration or to represent objects, as in relief. 2. A stained glass window executed according to this method.

grisaille glass 1. A white glass coating that produces an opalescent effect. 2. Glasswork having a light grey monotone color, often with an enameled pattern.

gristmill A mill for grinding grain; in earlier times powered by the wind, a stream, river, or by tidal water.

grit A granular abrasive material (e.g., consisting of particles of aluminum oxide or silicon carbide) which is used to coat cloth, paper, or wheels for sanding, grinding, or polishing; also used to provide a nonslip finish to a surface.

gritblast See sandblast.

grit trap Same as catch basin.

grizzly A stationary screen or series of equally spaced parallel bars set at an angle; used to remove oversize particles in processing aggregate or similar material.

grizzly brick Same as salmon brick.

grnd Abbr. for ground.

grog A crushed refractory material such as crushed firebrick or crushed pottery; used in the manufacture of products designed to withstand extreme heat.

groin The ridge, edge, or curved line formed by the intersection of the surfaces of two intersecting vaults.

groin arch, groined arch One arched division of cross vaulting.

groin centering 1. In groining without ribs, the centering of timber extended during construction under the whole surface. 2. In ribbed or groined work, the centering for the stone ribs, which need support until their arches are closed, after which the supports for the filling of the spandrils are sustained by the ribs themselves.

groined 1. Having groins. 2. Showing the curved lines resulting from the intersection of two semicylinders or arches.

groined rib A rib under the curve of a groin, either to mask the groin or to support it.

groined vault, groin vault A compound vault in which barrel vaults intersect, forming arrises called groins.

groining Any system of vaulting implying the intersection, at any angle, of simple vaults.

groin rib See groined rib.

groin vault Same as groined vault.

grommet A metal or plastic eyelet which provides a reinforced hole for attachment.

groove A long narrow cut in the edge or face of a wood member; a groove across the grain is a dado; one parallel with the grain is a plow.

grooved joint A joint used to connect two steel pipes or ductile-iron pipes; employs an inner elastomeric gasket and an outer split-metallic sleeve with an integral bolt for tightening the assembly.

grooved seam A seam in which the edges of two metal sheets are bent approximately 180°, inserted in each other, flattened, and then locked by pressure.

groove joint A construction joint formed by a groove in a floor slab, wall, or pavement; used to control random cracking.

groover A tool used to form grooves in a concrete slab before hardening; used to control crack locations or provide patterns.

groove weld A weld made in a preformed groove between two members to be joined.

grooving plane A plane, 1 used in carpentry, esp. to cut grooves in wood.

gross area, gross cross-sectional area Of a concrete masonry unit, the total area of a section perpendicular to the direction of the load, including areas within the cells of the unit and within reentrant spaces, unless these spaces are occupied by portions of adjacent masonry.

gross building area The total area of a building; usually expressed in square feet or square meters.

gross density of housing The maximum number of dwelling units allowed per unit area under applicable zoning regulations; often expressed in dwellings per acre or dwellings per hectare.

gross floor area The area within the perimeter of the outside walls of a building as measured from the inside surface of the exterior walls, with no deduction for hallways, stairs, closets, thickness of walls, columns, or other interior features; used in determining the required number of exits or in determining occupancy classification. Also see net floor area.

gross leasable area The total floor area designed for tenant occupancy and tenant use.

gross lease A lease in which the owner receives the contractual rent out of which he or she must pay all or most of the operating expenses of the real estate.

gross load In heating, the net load plus allowances for piping losses and for pickup.

gross output The available number of Btu at a boiler outlet nozzle for satisfying the gross load continuously, while the boiler is operating under applicable code limitations.

gross section Of a structural member, the total area of the cross section, making no deductions for holes within the cross section.

gross volume 1. In a revolving-drum concrete mixer, the total interior volume of the revolving portion of the mixer drum. 2. In an open-top mixer, the total volume of the trough, assuming that no vertical dimension of the container exceeds twice the radius of the circular section below the axis of the central shaft.

gross wall area The area of a wall including any openings, such as doors or windows, in the wall.

grotesque Sculptured or painted ornament involving fanciful distortions of human and animal forms, sometimes combined with plant motifs, esp. a variety of arabesque which has no counterpart in nature.

grotto A natural or artificial cave, often decorated with shells or stones and incorporating waterfalls or fountains.

ground 1. A nailing strip fixed in a masonry or concrete wall as a means of attaching wood trim or furring strips; also called a common ground, rough ground, fixing, fixing fillet, fixing slip. 2. A plaster ground. 3. The side of an electric circuit connected to the earth, used as a common return.

ground anchor A device used to secure a structure from lateral or vertical forces.

ground bar An electrical conductor which forms a common junction for a number of ground conductors.

ground beam 1. A groundsill. 2. A horizontal heavy timber or reinforced concrete beam at or near ground level for distributing a load which it supports.

ground brush An oval or round paintbrush used for covering large areas.

ground bus A bus to which grounds, 3 from individual pieces of equipment are connected; the bus, in turn, is connected to the ground at one or more points.

ground casing The blind casing of a window.

ground coat 1. A first coat of paint or enamel, particularly when designed to show through a topcoat. 2. A porcelain enamel applied directly to the base metal to function as an intermediate layer between the metal and the cover coat.

ground conductor An electrical conductor which provides an electrical connection between (a) the frame of a piece of equipment or part of a system and (b) a ground bar or ground electrode.

ground course The horizontal base course of masonry on the ground.

ground cover 1. Low planting, often maintenance-free, used in masses. 2. A thin plastic sheet, or the like, spread over the ground in a crawl space to minimize moisture penetration.

grounded Said of an electrical device, piece of equipment, or electrical system that is connected to the earth or to some extended electrically conducting body that serves as the earth, whether the connection is intentional or accidental.

grounded conductor An electric system or circuit conductor which is intentionally grounded.

grounded system A system of electric conductors in which at least one conductor is intentionally grounded, either solidly or through a current-limiting device.

grounded work Joinery, such as a chair rail, which is attached to a metal or wood ground.

ground electrode An electrical conductor (or group of conductors) in intimate contact with the ground; used to provide an effective electrical connection with the ground.

ground-faced block A concrete block whose exposed surfaces are ground smooth.

ground fault 1. An electrical short-circuit involving one or more phase conductors and ground. 2. An insulation fault between a conductor and ground or the frame of a device.

ground fault circuit interrupter (GFCI) A type of ground fault protection in areas where personnel are at high risk of receiving electrical shocks (for example, in damp locations); makes use of a device designed to trip at a ground current in the milliampere range, i.e., very much below currents that are normally harmful.

ground fault protection Protection against short-circuits produced by ground faults; may be provided by circuit breakers, relays, or ground fault circuit interrupters.

ground fill See fill, 1.

ground floor The floor of a building which is nearest the surrounding surface of the ground; usually the first floor in the US but sometimes a floor between a basement or cellar and the first floor.

ground glass Glass having a surface that has been roughened, usually by sandblasting or by acid, to make it nontransparent.

grounding conductor A conductor used to connect electric equipment or the grounded circuit of an electric wiring system to a grounding electrode or electrodes.

grounding electrode A conductor embedded in the earth, used to maintain ground potential on the conductors connected to it.

grounding electrode conductor The electrical conductor used to connect the grounding electrode to the equipment grounding conductor and/or the grounded conductor of the circuit at the service equipment.

grounding outlet An electric outlet which is equipped with a receptacle of the polarity type with an additional contact for the connection of an equipment grounding conductor.

grounding plug, grounding-type plug A plug, 5 having a blade which provides a ground connection for an electric device.

grounding system A system of interconnected grounds, 3.

ground investigation Same as site investigation. Also see geotechnical investigation.

ground joint 1. A closely fitted joint in masonry, usually without mortar. 2. A machined metal joint which fits tightly without packing or a gasket.

ground joist A joist which rests on sleepers laid on the ground, stones, or dwarf walls; used in basements or ground floors.

ground-key faucet A faucet through which flow is controlled by a slightly tapered plug with a hole in it; when the faucet is on, the fluid flows through the hole; when the plug is turned through 90°, the flow is stopped.

ground-key valve A valve which controls fluid flow in a manner similar to a ground-key faucet.

ground lease A legal contract for the lease of land; contains an agreement that the lessee is obligated to pay rent each year for the use of the land for the duration of the contract; the lessee usually builds on the land but the buildings so constructed must be turned over to the land’s owner at the termination of the contract.

ground level See ground line.

ground light Visible radiation from the sun and sky which is reflected by surfaces below the plane of the horizon.

ground line The level of the surface of the ground, above (or below) which the height of a structure (or depth of excavation) is measured.

ground niche A niche whose base is on a level with the floor.

ground plan, ground plot The plan of a building taken at ground level.

ground plane The horizontal plane of projection in a perspective drawing; the horizontal plane upon which the object in the drawing rests.

ground plate A groundsill.

ground rent The legally-contracted rent paid annually according to the terms of a ground lease.

ground ring A bare copper wire, laid underground in the shape of a loop around the exterior of a building; at the corners of the building and other appropriate locations, ground rods are installed and connected to the loop.

ground rod A metal rod or pipe which is driven into the ground to provide an electrical connection to the earth. Usually, the deeper the rod is driven beneath the earth’s surface, the lower its electric resistance to ground.

groundsel Same as groundsill.

ground sign A sign supported by uprights or braces in or upon the surface of the ground.

groundsill, ground beam, ground plate, mudsill, sole plate In a framed structure, the sill which is nearest the ground or on the ground; used to distribute concentrated loads.

ground story Same as ground floor.

ground table, earth table, grass table A projecting course or plinth resting immediately upon the foundation; the lowest course visible above the ground.

ground wall The foundation wall of a building.

groundwater Water, near the surface of the ground, which passes through the subsoil.

groundwater level At a particular site, the level below which the subsoil and rock masses of the earth are fully saturated with water.

groundwater recharge See recharge.

ground wire 1. A conductor leading to an electric connection to the earth. 2. A wire used to establish line and grade, as in shotcrete work; usually of small-gauge, high-strength steel.

groundwork Batten strips applied over roofing boards or the like; used as a base for the application of roofing materials.

grouped columns Three or more closely spaced columns forming a group, often on one pedestal.

grouped pilasters Three or more closely spaced pilasters forming a group, often on one pedestal.

group house, row house One of an unbroken line of houses having a common wall or party wall with its neighbors.

group relamping Replacing all lamps in a lighting system at one time. Also see spot relamping.

group vent In plumbing, a branch vent that serves two or more traps.

grout 1. Mortar containing a considerable amount of water so that it has the consistency of a viscous liquid, permitting it to be poured or pumped into joints, spaces, and cracks within masonry walls and floors, between pieces of ceramic clay, slate, and floor tile, and into the joints between preformed roof deck units. 2. In foundation work, mixtures of cement, cement-sand, clay, or chemicals; used to fill voids in granular soils, usually by a process of successive injection through drilled holes.

grouted-aggregate concrete Concrete that is formed by injecting grout into previously placed coarse aggregate.

grouted frame A hollow-metal doorframe which is completely filled with cement or mortar.

grouted masonry 1. Concrete masonry construction composed of hollow units where the hollow cells are filled with grout. 2. Multi-withe construction in which space between withes is solidly filled with grout.

grouting Filling the voids in or between aggregate, block, or tile with grout.

grouting sand Sand which passes through an 841µ (No. 20) sieve, and not more than 5% through a 74µ (No. 200) sieve.

grout pumping The placement of a liquid-like grout under pressure.

grout slope The natural slope assumed by fluid grout when injected into preplaced-aggregate concrete.

growth rate Rate of wood growth expressed as the number of annual rings per inch measured from pith to bark; sometimes used to rate softwoods for strength.

growth ring See annual ring.

grozing iron A hot iron used by plumbers for finishing soldered joints.

grub To clear a site by removing roots, stumps, and the like.

grub axe A tool for digging up roots or shrubs; a mattock.

grub saw A handsaw used for cutting stone, such as marble, into slabs for shelves, mantelpieces, etc.

grub screw See setscrew, 1.

grummet Same as grommet.

grundscheier A barn constructed by early German-speaking immigrants to America; of varied construction, depending on available materials and the terrain; usually built on slightly sloping ground. See German barn.

gryphon A griffin.

gryse See grees.

GSA Abbr. for “General Services Administration.”

guarantee 1. A legally enforceable assurance of the quality or duration of a product or of work, 1 performed. 2. A binding commitment by one person that another will perform his contract obligations satisfactorily.

guaranteed maximum cost An amount established in an agreement between owner and contractor as the maximum cost of performing specified work on the basis of cost of labor and materials plus overhead expense and profit.

guaranty bonds 1. See bid bond. 2. See labor and material payment bond. 3. See performance bond. 4. See surety bond.

guard bar Any bar serving as a protection or a means of security, as a window bar, 3 or window guard, 2.

guard bead 1. A corner bead. 2. A staff bead.

guard board A raised timber at the edge of a scaffold that prevents workers or tools from dropping off the edge of the platform.

guarded Enclosed, fenced, covered, shielded, or otherwise protected, by means of suitable barriers, rails, screens, covers or casings, mats, or platforms, to prevent dangerous contact.

guard rail For an automatically operated door, a railing used to separate and control traffic passing in opposite directions through the door.

guard post Same as bollard.

guardrail system A protective railing system along the outer edges of locations of an accessible roof, balcony, landing, platform, or ramp.

guard system A system of building components located near the open sides of elevated walking surfaces, designed to minimize the possibility of an accidental fall from the walking surface.

gudgeon A metal pin used to hold together two blocks or slabs, as of stone.

guesthouse 1. A separate residence for guests, as a house on a private estate or a boarding house of high standards. 2. A monastery building specifically for receiving visitors.

guest room 1. In a multiple-family dwelling, a room occupied or intended to be occupied for hire. 2. In a single-family or two-family dwelling, a room in the main or an accessory building occupied or intended to be occupied by nonpaying guests.

guglia An elongated finial.

guide bead Same as inside stop.

guide coat A thin coat of paint which highlights the bumps or imperfections in a sealer or filler beneath, and thus serves as a guide for rubbing them down.

guide pile A heavy, square timber which is driven vertically downward to guide steel sheet-piling.

guide rail A track that acts as a guide for a sliding window or door.

guide wire In a theater stagehouse: 1. A steel cable which guides the vertical movement of a curtain. 2. A line which guides the movement of a counterweight arbor.

guildhall A place of assembly for a society of craftsmen or merchants for their mutual assistance; an outgrowth of similar medieval organizations or guilds.

guilloche An ornament formed by two or more bands twisted over each other in a continuous series, leaving circular openings which are often filled with round ornaments.

guillotine Same as bench trimmer.

guillotine window Same as double-hung window.

gula 1. A molding having a large hollow. 2. A cyma. 3. A gorge.

gulbishche In early Russian architecture, a terrace which surrounds a building.

gullet The concave space between saw teeth.

gulley, gully In a drainage system, a fitting at the upper end of a drain that receives the discharge from waste pipes or rain water.

gum 1. A moderately high-density hardwood of the eastern and southern US; whitish to gray-green in color and of uniform texture; used for low-grade veneer, plywood, and rough cabinet work. 2. Any of a class of colloidal substances that are soluble or swell in water, exuded by or prepared from plants; sticky when moist.

gum arabic, acacia, gum acacia A white, powdery, water-soluble gum, extracted from certain acacia trees; used in the manufacture of adhesives and transparent paints.

gum bloom A defect in a painted surface, appearing as a lack of gloss or a haze, resulting from the use of incorrect reducer.

gumbo A fine-grained clay; very sticky when wet.

gum pocket See gum vein.

gum rosin See rosin.

gum seam In a piece of lumber, a check or shake filled with gum.

gum streak See gum vein.

gum vein, gum pocket, gum streak In hardwoods, a local accumulation or streak of resin.

gumwood Wood of the gum tree, esp. eucalyptus; used for interior trim.

gun 1. See spray gun. 2. A pressure cylinder for delivering freshly mixed concrete pneumatically. 3. Shotcrete material delivery equipment; also see shotcrete gun.

gun consistency See gun grade.

gun finish A layer of shotcrete as it is applied, without subsequent hand finishing.

gun grade, gun consistency A grade of caulking or glazing compound which has the proper softness for application by a caulking gun.

gun hole, gun loop, gun port, gun slot A type of embrasure in a structure designed to provide protection in case of enemy attack; the opening enables a defender to fire through a wall, over a wide angle.

Gunite A proprietary name for shotcrete.

gunning Applying material, e.g., shotcrete, with the use of a gun.

gun pattern The outline of material which is discharged by a gun, as in a shotcrete operation.

gunshot house Same as shotgun house.

gun-stock post Same as musket-stock post.

gunstock stile A diminished stile in which there is a gradual change in width between the broader and narrower parts.

Gunter’s chain A measuring device in land surveying, consisting of 100 metal links, equivalent to 66 ft in length.

gusset, gusset plate A plate, usually triangular in shape, used to connect two or more members, or to add strength to a framework.

gutta (pl. guttae) In Classical architecture, one of a number of pendant ornaments in a rectangular arrangement; each gutta is shaped like an inverted frustum of a cone, i.e., a cone in which the upper tip has been lopped off; usually found on the underside of the mutules of a Doric entablature.

guttae band Same as regula in the Greek Doric entablature.

gutter 1. A shallow channel of metal or wood set immediately below and along the eaves of a building to catch and carry off rainwater from the roof. Also see box gutter, concealed gutter, flying gutter, standing gutter, sunk gutter, through gutter. Also called eaves gutter, eaves trough, roof gutter. 2. In electrical wiring, the space provided at the sides, top, or bottom within an electric panel or switchboard to permit the installation of feeder and branch wiring conductors.

gutter bearer A member to which gutter boards are fixed.

gutter bed A sheet of flexible metal, over the wall side of a gutter along the eaves, which prevents overflow from penetrating the wall.

gutter board, gutter plank In a wood gutter along the eaves of a roof, a board on which the lining material of the gutter is laid.

guttered A term sometimes used to describe a structural framing member (such as a corner post) that is either encased or cut away to disguise its appearance.

gutter hook A light metal strap used to secure or support a metal gutter.

gutter plate 1. One of the sides of a box gutter. 2. A beam which supports a lead gutter.

gutter spout Same as downspout.

gutter tool A tool used to give the desired shape and finish to concrete gutters.

guy A supporting rope, cable, or wire which is anchored at one end and tied to an object or structure in order to stabilize it.

guy anchor A buried object used to secure a guy.

guy derrick A derrick comprised of a boom and a mast supported by wire rope guys.

GV Symbol for gate valve.

gymmer See gemel.

gymnasium 1. A large room or building devoted to physical education or indoor games. In addition to the playing floor, the building form usually contains staff offices, locker and shower rooms, and spectator facilities. 2. In continental Europe, a secondary school which prepares students for university. 3. In Greek and Roman architecture, a large open court for exercise, surrounded by colonnades and rooms for massage, lectures, etc.; a palaestra, ephebeion.

gynaeceum That part of a Greek house or a church reserved for women.

GYP On drawings, abbr. for gypsum.

gypsite Gypsum having a purity of from 60 to 90% and containing clay, loam, and sand.

gypsum A soft mineral consisting of a hydrated calcium sulfate from which gypsum plaster is made (by heating); colorless when pure; used as a retarder in portland cement.

gypsum backerboard A gypsum board used as a base on which to adhere tile or gypsum wallboard; similar to, but less smooth than, wallboard; is surfaced with a grayish paper.

gypsum block, gypsum tile, partition tile 1. A hollow or solid building block, fabricated of gypsum; used in a nonbearing partition; serves as a base for plastering. 2. A cast gypsum building block.

gypsum board A wallboard having a gypsum core. This noncombustible core has a paper surface.

gypsum cement See Keene’s cement.

gypsum concrete A mixture of a calcined gypsum binder and wood chips or other aggregate; when mixed with water, sets to a conglomerate mass; used for poured gypsum roof decks.

gypsum core board A gypsum board consisting of either a single board or factory laminated multiple boards for use as a gypsum stud or core in semisolid or solid gypsum board partitions; usually available in thicknesses from ¾ inch (19.0 mm) to 1 inch (25.4 mm).

gypsum fiber concrete Gypsum concrete in which the aggregate consists of shavings, fiber, or chips of wood.

gypsum formboard A gypsum board used as a permanent form for pouring gypsum roof decks.

gypsum insulation Gypsum in pellet form used as loose-fill thermal insulation.

gypsum lath, board lath, gypsum plasterboard, rock lath A base for plaster; a sheet having a gypsum core, faced with paper, which provides a good bond for plaster; usually manufactured in 16-in. by 48-in. (40.6-cm by 121.9cm) or 24-in. by 96-in. (61.0-cm by 243.8-cm) panels,

or ½ in. (0.95 or 1.27 cm) thick with round or square edges.