Glossary of Building Terms

Homeowner Glossary

Construction Terms

Vertical bars on stairs, more commonly called a “spindle”.

Base Moulding

Decorative trim board that covers the joint between the wall and the floor. Comes in a variety of sizes.

Bottom Plate

Horizontal framing member that supports wall studs on bottom, allowing the studs to be fastened to the foundation.

Single Hung Window

A window in which the sash slides up and down within a track.

Cement Board Siding

Siding made of fiber cement board, very durable and long lasting.

Engineered Wood

Wood products that are manufactured to precise design specifications and are tested to meet national or international standards.

Fascia Board

The trim piece that is nailed horizontally to the ends of rafters around the bottom of the roof (aluminum or wood). Gutters are mounted to the fascia.

Frieze Board

Horizontal trim piece installed at the top of an exterior wall that covers the joint between the soffit and the exterior wall.

Fire Blocking

A process in which penetrations in wall cavities are filled with fire retardant foam in order to prevent the spread of fire within a wall cavity.


Thin pieces of metal or other impermeable materials used to shed water away from entry into structure from exterior.


Heating, Ventilation, Air Conditioning.


Horizontal structural framing member that supports the load over a window or door opening.


Vertical portion of door frame on which door is secured.


Horizontal supporting member that runs from wall to wall, wall to beam, or beam-to-beam in which it supports a roof, ceiling, or floor

Oriented Strand Board

An engineered wood product that is used for walls, floor, and roofs. Made of thin chips of wood glued and pressed together.

Pressure Treated Lumber

Wood that has been treated with a preservative to protect it from being destroyed by insects, fungus, and weathering.


A type of beam that supports the roof of a building.

Rafter Tail

Portion of rafter that extends beyond the wall plate.


Steel bars that are used to reinforce concrete.


The thermal resistance to heat loss in a material, the higher the R-value, the better the insulation.


Part of roof where roof comes to a point.


The vertical portion of the stair step


Plywood and DOW 1" foam applied to the outer studs, and rafters to strengthen the structure and serve as a weatherproofing membrane.


Horizontal board at the bottom of a window or door frame.


The underside of an overhang of a roof structure.

Top Plate

Top horizontal framing member of a building frame in which rafters are fastened to.

Casement Window

A window in which the sash swings out via a cranking mechanism.


The portion of the stair step that you make contact with when stepping.