What is a Collar in roofing terms?

• A. A gasket used to seal around vent penetrations.
• B. Pre-formed flange placed over a vent pipe to seal the roof around the vent pipe opening; also called a vent sleeve.
• C. A decorative cap used on vent pipes.
• D. An alternate term for ridge vent.

Answer: (B)

A collar in roofing terms is the pre-formed flange that fits around a vent pipe where it penetrates the roof, forming the watertight transition between the pipe and the roof surface. It sits at the roof opening and is the base that flashing and shingles seal against, preventing water from seeping where the pipe passes through. This piece is often called a vent sleeve, since it functions as a sleeve around the pipe. The decorative cap sits on top of the pipe and doesn’t seal the roof opening, ridge vent runs along the ridge and isn’t around a pipe, and a gasket around penetrations isn’t the same as the flange that surrounds the pipe and integrates with flashing.