Glossary of Siding Terms

Backerboard: A flat material used on the face of the house, between the studs and the siding, to provide a nailable surface for the siding.

Buttlock: The bottom edge of a siding or soffit panel, or accessory piece, opposite the nailing slots, which locks onto the preceding panel.

Channel: The area of the accessory trim or corner post where siding or soffit panels are inserted. Channels also refer to the trim itself, and are named for the letters of the alphabet they resemble (e.g., J-channel, F-channel, etc.).

Course: A row of panels, one panel wide, running the length of the house from one side to the other or, in the case of vertical siding, from top to bottom.

Face: Refers to the side of a siding or soffit panel that is showing once the panel has been installed.

Fascia Board: A board attached to the ends of the rafters between the roofing material and the soffit overhang. Fascia cap is the covering around that board.

Lap: To overlap the ends of two siding panels or accessory pieces to allow for expansion and contraction of the vinyl product.

Soffit: Material used to enclose the horizontal underside of an eave, cornice, or overhang. Some soffit panels may also be used as vertical siding.

Starter Strip: An accessory applied directly to the surface of the building and used to secure the first course of siding to the home.

Underlayment: Weather-resistant material placed under vinyl siding panels.

Weep Holes: Openings cut into siding or accessories to allow for water runoff.