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.