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Homeowner's Glossary of Building Terms
U.S. Department of Housing and Urban Development

A B C D E
F G H I J
K L M N O
P Q R S T U
V W X Y Z

This publication defines some terms used in home construction, repair and maintenance. It is not a comprehensive list but will provide a quick reference for homeowners who are unfamiliar with building terminology.

A

Acoustical Tile

Special tile for walls and ceilings made of mineral, wood, vegetable fibers, cork, or metal. Its purpose is to control sound volume, while providing cover.

Air Duct

Pipes that carry warm air and cold air to rooms and back to furnace or air conditioning system.

Ampere

The rate of flow of electricity through electric wires.

Apron

A paved area, such as the juncture of a driveway with the street or with a garage entrance.

B

Backfill

The gravel or earth replaced in the space around a building wall after foundations are in place.

Balusters

Upright supports of a balustrade rail.

Balustrade

A row of balusters topped by a rail, edging a balcony or a staircase.

Baseboard

A board along the floor against walls and partitions to hid gaps.

Batt

Insulation in the form of a blanket, rather than loose filling.

Batten

Small thin strips covering joints between wider boards on exterior building surfaces.

Beam

One of the principal horizontal wood or steel members of a building.

Bearing Wall

A wall that supports a floor or roof of a building.

Bib or Bibcock

A water faucet to which a hose may be attached, also called a hose bib or sill cock.

Bleeding

Seeping of resin or gum from lumber. This term is also used in referring to the process of drawing air from water pipes.

Brace

A piece of wood or other material used to form a triangle and stiffen some part of a structure.

Braced Framing

Construction technique using posts and cross-bracing for greater rigidity.

Brick Veneer

Brick used as the outer surface of a framed wall.

Bridging

Small wood or metal pieces placed diagonally between floor joists.

Building Paper

Heavy paper used in walls or roofs to dampproof.

Built-Up Roof

A roofing material applied in sealed, waterproof layers, where there is only a slight slope to the roof.

Butt Joint

Joining point of two pieces of wood or molding.

Bx Cable

Electricity cable wrapped in rubber with a flexible steel outer covering.

C

Cantilever

A projecting beam or joist, not supported at one end, used to support an extension of a structure.

Carriage

The member which supports the steps or treads of a stair.

Casement

A window sash that opens on hinges at the vertical edge.

Casing

Door and window framing.

Cavity Wall

A hollow wall formed by firmly linked masonry walls, providing an insulating air space between.

Chimney Cap

Concrete capping around the top of chimney bricks and around the floors to protect the masonry from the elements.

Chair Rail

Wooden molding on a wall around a room at the level of a chair back.

Chamfered Edge

Molding with pared-off corners.

Chase

A groove in a masonry wall or through a floor to accommodate pipes or ducts.

Chimney Breast

The horizontal projection-usually inside a building-of a chimney from the wall in which it is built.

Circuit Breaker

A safety device which opens (breaks) an electric circuit automatically when it becomes overloaded.

Cistern

A tank to catch and store rain water.

Clapboard

A long thin board, thicker on one edge, overlapped and nailed on for exterior siding.

Collar Beam

A horizontal beam fastened above the lower ends of rafters to add rigidity.

Coping

Tile or brick used to cap or cover the top of a masonry wall.

Corbel

A horizontal projection from a wall, forming a ledge or supporting a structure above it.

Corner Bead

A strip of wood or metal for protecting the external corners of plastered walls.

Cornice

Horizontal projection at the top of a wall or under the overhanging part of the roof.

Course

A horizontal row of bricks, cinder blocks or other masonry materials.

Cove Lighting

Concealed light sources behind a cornice or horizontal recess which direct the light upon a reflecting ceiling.

Crawl Space

A shallow, unfinished space beneath the first floor of a house which has no basement, used for visual inspection and access to pipes and ducts. Also, a shallow space in the attic, immediately under the roof.

Cripples

Cut-off framing members above and below windows.

D

Door Buck

The rough frame of a door.

Dormer

The projecting frame of a recess in a sloping roof.

Double Glazing

An insulating window pane formed of two thicknesses of glass with a sealed air space between them.

Double Hung Windows

Windows with an upperand lower sash, each supported by cords and weights.

Downspout Leader

Downspout A spout or pipe to carry rain water down from a roof or gutters.

Cripples

A pipe for conducting rainwater from the roof to a cistern or to the ground by way of a downspout.

Downspout Strap

A piece of metal which secures the downspout to the eaves or wall of a building.

Drip

The projecting part of a cornice which sheds rain water.

Dry Wall

A wall surface of plasterboard or material other than plaster.

E

Eaves

The extension of roof beyond house walls.

Efflorescence

White powder that forms on the surface of brick.

Effluent

Treated sewage from a septic tank or sewage treatment plant.

F

Fascia

A flat horizontal member of a cornice placed in a vertical position.

Fill-Type Insulation

Loose insulating material which is applied by hand or blown into wall spaces mechanically.

Flashing

Noncorrosive metal used around angles or junctions in roofs and exterior walls to prevent leaks.

Floor Joists

Framing pieces which rest on outer foundation walls and interior beams or girders.

Flue

A passageway in a chimney for conveying smoke, gases or fumes to the outside air.

Footing

Concrete base on which a foundation sits.

Foundation

Lower parts of walls on which the structure is built. Foundation walls of masonry or concrete are mainly below ground level.

Framing

The rough lumber of a house-joists, studs, rafters, and beams.

Furring

Thin wood, or metal applied to a wall to level the surface for lathing, boarding, or plastering, to create an insulating air space, and to damp proof the wall.

Fuse

A short plug in an electric panel box which opens (breaks) an electrical circuit when it becomes overloaded.

G

Gable

The triangular part of a wall under the inverted "v" of the roof line.

Gambrel Roof

A roof with two pitches, designed to provide more space on upper floors. The roof is steeper on its lower slope and flatter toward the ridge.

Girder

A main member in a framed floor supporting the joists which carry the flooring boards. It carries the weight of a floor or partition.

Glazing

Fitting glass into windows or doors.

Grade Line

The point at which the ground rests against the foundation wall.

Green Lumber

Lumber which has been inadequately dried and which tends to warp or "bleed" resin.

Grounds

Pieces of wood embedded in plaster of walls to which skirtings are attached. Also wood pieces used to stop the plaster work around doors and windows.

Gusset

A brace or bracket used to strengthen a structure.

Gutter

A channel at the eaves for conveying away rain water.

H

Hardwood

The close-grained wood from broad-leaved trees such as oak or maple.

Headers

Double wood pieces supporting joists in a floor or double wood members placed on edge over windows and doors to transfer the roof and floor weight to the studs.

Heel

The end of a rafter that rests on the wall plate.

Hip Roof

A roof that slants upward on three or four sides.

Hip

The external angle formed by the juncture of two slopes of a roof.

J

Jalousies

Windows with movable, horizontal glass slats angled to admit-ventilation and keep out rain. This term is also used for outside shutters of wood constructed in this way.

Jamb

An upright surface that lines an opening for a door or window.

Joist

A small rectangular sectional member arranged parallel from wall to wall in a building, or resting on beams or girders. They support a floor or the laths or furring strips of a ceiling.

K

Kiln-Dried

Artificial drying of lumber, superior to most lumber that is air dried.

King-Post

The middle post of a truss. Large, heavy screws, used where great strength is required, as in heavy framing or when attaching ironwork to wood.

L

Lag-Screws or Coach-Screws

Large, heavy screws, used where great strength is required, as in heavy framing or when attaching ironwork to wood.

Lally Column

A steel tube sometimes filled with concrete, used to support girders or other floor beams.

Lath

One of a number of thin narrow strips of wood nailed to rafters, ceiling joists, wall studs, etc. to make a groundwork or key for slates, tiles, or plastering.

Leaching Bed

Tiles in the trenches carrying treated wastes from septic tanks.

Ledger

A piece of wood which is attached to a beam to support joists.

Lintel

The top piece over a door or window which supports walls above the opening.

Load-Bearing Wall

A strong wall capable of supporting weight.

Louver

An opening with horizontal slats to permit passage of air, but excluding rain, sunlight and view.

M

Masonry

Walls built by a mason, using brick, stone, tile or similar materials.

Molding

A strip of decorative material having a plane or curved narrow surface prepared for ornamental application. These strips are often used to hide gaps at wall junctures.

Moisture Barrier

Treated paper or metal that retards or bars water vapor, used to keep moisture from passing into walls or floors.

Mullion

Slender framing which divides the lights or panes of windows.

N

Newel

The upright post or the upright formed by the inner or smaller ends of steps about which steps of a circular staircase wind. In a straight flight staircase, the principal post at the foot or the secondary post at a landing.

Nosing

The rounded edge of a stair tread.

P

Parging

A rough coat of mortar applied over a masonry wall as protection or finish; may also serve as a base for an asphaltic waterproofing compound below grade.

Pilaster

A projection or the foundation wall used to support a floor girder or stiffen the wall.

Pitch

The angle of slope of a roof.

Plasterboard (See Dry Wall)

Gypsum board, used instead of plaster.

Plates

Pieces of wood placed on wall surfaces as fastening devices. The bottom member of the wall is the sole plate and the top member is the rafter plate.

Plenum

A chamber which can serve as a distribution area for heating or cooling systems, generally between a false ceiling and the actual ceiling.

Pointing

Treatment of joints in masonry by filling with mortar to improve appearance or protect against weather.

Post-And-Beam Construction

Wall construction in which beams are supported by heavy posts rather than many smaller studs.

Prefabrication

Construction of components such as walls, trusses, or doors, before delivery to the building site.

R

Rabbet

A groove cut in a board to receive another board.

Radiant Heat

Coils of electricity, hot water or steam pipes embedded in floors, ceilings, or walls to heat rooms.

Rafter

One of a series of structural roof members spanning from an exterior wall to a center ridge beam or ridge board.

Reinforced Concrete

Concrete strengthened with wire or metal bars.

Ridge Pole

A thick longitudinal plank to which the ridge rafters of a roof are attached.

Riser

The upright piece of a stair step, from tread to tread.

Roof Sheathing

Sheets, usually of plywood, which are nailed to the top edges of trusses or rafters to tie the roof together and support the roofing material.

S

Sandwich Panel

A panel with plastic, paper, or other material enclosed between two layers of a different material.

Sash

The movable part of a window-the frame in which panes of glass are set in a window or door.

Scotia

A concave molding.

Scuttle Hole

A small opening either to the attic, to the crawl space or to the plumbing pipes.

Seepage Pit

A sewage disposal system composed of a septic tank and a connected cesspool.

Septic Tank

A sewage settling tank in which part of the sewage is converted into gas and sludge before the remaining waste is discharged by gravity into a leaching bed underground.

Shakes

Handcut wood shingles.

Sheathing (See Wall Sheathing)

The first covering of boards or material on the outside wall or roof prior to installing the finished siding or roof covering.

Shim

Thin tapered piece of wood used for leveling or tightening a stair or other building element.

Shingles

Pieces of wood, asbestos or other material used as an overlapping outer covering on walls or roofs.

Shiplap

Boards with rabbeted edges overlapping.

Shiplap

Siding Boards of special design nailed horizontally to vertical studs with or without intervening sheathing to form the exposed surface of outside walls of frame buildings.

Sill Plate

The lowest member of the house framing resting on top of the foundation wall. Also called the mud sill.

Skirtings

Narrow boards around the margin of a floor; baseboards.

Slab

Concrete floor placed directly on earth or a gravel base and usually about four inches thick.

Sleeper

Strip of wood laid over concrete floor to which the finished wood floor is nailed or glued.

Soffit

The visible underwide of structural members such as staircases, cornices, beams, a roof overhang or eave.

Softwood

Easily worked wood or wood from a conebearing tree.

Soil Stack

Vertical plumbing pipe for waste water.

Stringer

A long, horizontal member which connects uprights in a frame or supports a floor or the like. One of the enclosed sides of a stair supporting the treads and risers.

Studs

In wall framing, the vertical members to which horizontal pieces are nailed. Studs are spaced either 16 inches or 24 inches apart.

Subfloor

Usually, plywood sheets that are nailed directly to the floor joists and that receive the finish flooring.

Sump

A pit in the basement in which water collects to be pumped out with a sump pump.

Swale

A wide shallow depression in the ground to form a channel for storm water drainage.

T

Tie

A wood member which binds a pair of principal rafters at the bottom.

Tile Field

Open-joint drain tiles laid to distribute septic tank effluent over an absorption area or to provide subsoil drainage in wet areas.

Toenail

Driving nails at an angle into corners or other joints.

Tongue-And-Groove

Carpentry joint in which the jutting edge of one board fits into the grooved end of a similar board.

Trap

A bend in a water pipe to hold water so gases will not escape from the plumbing system into the house.

Tread

The horizontal part of a stair step.

Truss

A combination of structural members usually arranged in triangular units to form a rigid framework for spanning between load-bearing walls.

V

Valley

The depression at the meeting point of two roof slopes.

Vapor Barrier

Material such as paper, metal or paint which is used to prevent vapor from passing from rooms into the outside walls.

Venetian Window

A window with one large fixed central pane and smaller panes at each side.

Vent Pipe

A pipe which allows gas to escape from plumbing systems.

Verge

The edge of tiles, slates or shingles, projecting over the gable of a roof.

W

Wainscoting

The lower three or four feet of an interior wall when lined with paneling, tile or other material different from the rest of the wall.

Wall Sheathing

Sheets of plywood, gypsum board, or other material nailed to the outside face of studs as a base for exterior siding.

Weather Stripping

Metal, wood, plastic or other material installed around door and window openings to prevent air infiltration.

Weep Hole

A small hole in a wall which permits water to drain off.


U.S. Department of Housing and Urban Development
451 Seventh Street SW
Washington DC 20410
July 1996

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