Constructions Terms / Glossary

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Air Duct – Pipes that carry warm and cold air to rooms and back to the climate control system.
Baffle – Cardboard or other stiff paper product installed in the attic at the point where a wooden roof rafter passes over the exterior wall. Its purpose is to maintain a clear area for the air to pass from a soffit vent into the attic space.
Baseboard – A board placed along the floor against walls and partitions to hide gaps.
Batt – Insulation in the form of a blanket, rather than loose.
Beam – One of the principle horizontal wood or steel members of a building.
Bearing wall – A wall that supports a floor or roof of a building.
Brace – A piece of wood or other material used to form a triangle to stiffen or reinforce part of a structure.
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 to damp-proof walls or roofs.
Built-up roof – A roofing material applied to sealed, waterproof layers where there is only a slight slope to the roof.
Cantilever – A projecting beam or joist, not supported at one end, used to support an extension of a structure.
Ceiling joist – A joist that carries the ceiling beneath it but not the floor over it. Normally the ceiling is carried on the underside of floor joists, but to improve the noise insulation between floors, the ceiling joists may be separate.
Chimney cap – Concrete or metal covering over and above the chimney opening to prevent rain from entering the chimney.
Chair rail – Wooden molding on a wall at the height of a chair back.
Chase – An enclosed opening through a floor and/or ceiling to install pipes, ductwork or electrical lines.
Circuit breaker – Safety devices that open or break an electrical circuit automatically when it is overloaded.
Clapboard – A long, thin board, thicker on one edge, used for overlapping exterior siding.
Collar beam – A horizontal beam fastened above the lower ends of rafters to add rigidity.
Corbel – A horizontal projection from a wall, forming a ledge or supporting the structure above it, usually built with masonry.
Cornice – An overhanging molding at the top of an outside wall to direct drips away from the wall, or where an inside wall joins the ceiling.
Course – A horizontal row of bricks, concrete block or other masonry materials.
Crawlspace – A shallow, unfinished space beneath the first floor of a house that has no basement, used to visually inspect and to access pipes and ducts.
Cripples – Cut-off framing members above and below windows.
Door buck – The rough frame of a door.
Dormer – The projecting frame of a recess in a sloping roof.
Double-glazing – An insulating windowpane formed of two thicknesses of glass with a sealed air space between them.
Double hung windows – Windows with an upper and lower sash, each supported by springs.
Downspout – A spout or pipe to carry rainwater from a roof or from gutters.
Drywall – A thin plaster wall surface of gypsum board or other material.
Eaves – The overhanging extension of a roof beyond the walls of a house.
Efflorescence – A white powder that forms on the surface of brick.
Fascia board – A board set on edge, fixed to the rafter ends or wall plate that carries the gutter under an eave.
Fill-type insulation – Loose insulating material that is applied by hand or blown into wall spaces mechanically.
Flashing – A non-corrosive material used around angles or junctions in roofs and exterior walls to prevent leaks.
Floor joists – Framing pieces that typically 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 – The concrete base upon which a foundation rests.
Foundation – Lower parts of walls upon which a structure is built. Foundation walls of masonry or concrete usually are below ground level.
Framing – The rough lumber for house-joists, studs, rafters and beams.
Frost line – An imaginary line indicating the depth of frost penetration in the ground.
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 a wall.
Gable – The triangular part of a wall beneath the inverted “V” of the roofline.
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 supports the weight of a floor or partition.
Glazing – Fitting glass into windows or doors.
Grade line – The point at which the foundation wall rests against the ground.
Headers – Double wood pieces supporting joists in a floor, or double wood members placed on edge over windows and doors to transfer the weight of the roof and floor to studs.
Heel – The end of a rafter that rests on a wall plate.
Hip roof – Roofs that slant upward on three of four sides.
Hip – The external angle formed by the juncture of two slopes of a roof.
Jamb – An upright surface that lines an opening for a door or window.
Joist – A small rectangular sectional member arranged at a parallel angle from wall to wall or resting on beams or girders. They support a floor or the laths or furring strips of a building.
Kiln-dried – Artificial drying of lumber, superior to most air-dried lumber.
King post – The middle post of a truss.
Lag or coach screws – Large, heavy screws used where great strength is required, as in heavy framing, or when attaching ironwork to wood.
Ledger – A piece of wood attached to a beam on which a joist rests.
Lintel – The top piece over a door or window that supports the walls above the opening.
Load-bearing wall – A strong wall capable of supporting weight.
Louver – An opening with horizontal slats to permit the passage of air, but excluding rain, sunlight and view.

Masonry – Walls built by a mason using brick, stone, tile or similar material.
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 that divides the lights or panes of a window.
Newel – The upright post or an upright structure formed by the inner or smaller ends of steps around which the steps of a circular stairway wind. In a straight flight staircase, the principle post at the foot or a secondary post at a landing.
Nosing – The rounded edge of a stair tread
Parging – A rough coat of mortar applied over a masonry wall as protection or finish. It may also serve as a base for an asphalt waterproofing compound below grade.
Pier – A column designed to support a concentrated load. A member, usually in the form of a thickened section which forms an integral part of a wall; usually placed at intervals along the wall to provide lateral support or to support concentrated vertical walls.
Pilaster – A projection of the foundation wall used to support a floor girder or stiffen the wall.
Pitch – The angle or slope of a roof or a sewage line.
Plasterboard (see dry wall) – Gypsum board, used in place of plaster.
Plates – Pieces of wood placed on wall surfaces as fastening devices. The bottom member of a wall is the sole plate and the top member is the rafter plate.
Plenum – A chamber that serves as an air distribution area for heating or cooling systems. Generally placed between a false ceiling and the actual ceiling.
Prefabrication – Construction of components, such as walls, trusses or doors, before delivery to the building site.
Rafter – One of a series of structural roof members spanning an exterior wall to a center ridge beam or ridge board.
Reinforced concrete rods – Concrete strengthened with steel.
Ridge board – A horizontal board set on edge at which rafters meet.
Ridgepole – 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 made of plywood, which are nailed to the top edges of trusses or rafters to tie the roof together and support the roofing material.
Sash – The movable part of a window – the frame into which panes of glass are set in a window or door.
Scuttle hole – A small opening either to the attic or to the crawl space.
Septic tank – Holding tank for sewage solids used to break it down into smaller particles before it flows into a drain field and is eventually absorbed into the ground.
Shakes – Hand cut wooden shingles.
Sheathing (see wall sheathing) – The first covering of boards or material on an outside wall or roof prior to installing the finished siding or roof covering.
Shingles – Pieces of wood, asbestos or other material used as an overlapping outer covering on walls or roofs.
Siding – Boards of special design nailed horizontally to vertical studs with or without intervening sheathing to form the exposed surface of the outside walls of frame buildings.
Sill plate – The lowest member of the house framing which rest on top of the foundation wall. Also called a mudsill.
Slab – A concrete floor placed directly on an earth or a gravel base – usually approximately 4 inches thick.
Sleeper – A strip of wood laid over a concrete floor to which a finished wood floor is nailed or glued.
Soffit – The visible underside of structural members, such as staircases, cornices, beams, roof overhangs, or eaves.
Soil stack – A vertical plumbing pipe for wastewater.
Sole Plate – A horizontal timber that serves as a base for the studs in a stud partition.
Shim – A thin tapered piece of wood used for leveling a building element.
Stringer – A long horizontal member that connects the uprights in a frame or supports a floor or similar structure or 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 or 24 inches apart.
Sub floor – Sheets of plywood that are nailed directly to the floor joists that receive the finish flooring.
Swale – A wide, shallow depression in the ground to form a channel for water drainage.
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 where 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 that usually are arranged in triangular units to form a rigid framework for spanning long distances without a mid-support.
Valley – The depression at the meeting joint of two roof slopes.
Vapor barrier – Material, such as paper, metal or paint which is used in the interior of a house to prevent vapor from passing into the outside walls.
Vent pipe – A pipe that allows gases to escape from plumbing systems into the air above a roof.
Wainscoting – The lower 3 or 4 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 masonry wall which permits water to drain.