What is the deck?

• A. The surface, installed over the supporting framing members, to which the roofing is applied.
• B. The topmost layer visible on a finished roof.
• C. The ventilation opening at the ridge.
• D. The overlapping layer of shingles at the eave.

Answer: (A)

The deck is the base surface built on top of the roof framing that roofing materials are attached to. It’s typically plywood or OSB sheathing, providing a flat, solid substrate and nail-hold for the shingles or other roofing. This layer sits beneath underlayment and the finished roofing, so it’s not the visible top layer, not a ventilation opening at the ridge, and not the overlapping shingles along the eave.