How to Install B-Vent Flashing

Slide the metal B-vent flashing collar over the B-vent exiting the roof line.

Position it in its final resting position on the shingle surface and choose the row of shingles that's parallel to the peak side of the B-vent circumference. The shingle row must begin slightly before the pipe.

Slide the flashing slightly up the pipe and bend it downward so that the flat metal edge of the flashing is aligned with the shingle row. Work the flat metal edge under the shingles. Be careful not to damage the roof surface.

Slide the flashing back into its final resting position with the top section under the shingles. Hammer three roofing nails through the bottom flange of the flashing and into the wood roof surface.

Apply roofing cement to the top of each of the three nails, around the sides and bottom of where the flashing meets the shingles, and around where the flashing meets the pipe. A little attention to detail when applying the roofing cement prevents future leaks.