How to Install Flashing Around Roof Vents

Position a sturdy extension ladder against the roof. Anchor the feet to the ground with wooden garden stakes to prevent the ladder slipping.

Unzip the back of an easy chair cushion cover and remove the foam rubber square. Climb onto the roof and place the foam rubber square close to the defective roof vent to act as nonslip working platform.

Carefully peel back the shingles covering the upper half of the galvanized sheet metal vent pipe flashing. Slide a flat pry bar between the shingles and the nails securing the flashing to the roof and pry the nail heads gently upward; try not to tear the shingles. Once there is space between the nail heads and the shingles pry the nails out from the top.

Repeat by removing the nails from the exposed bottom half of the flashing.

Lift the upper shingles, grasp the thin galvanized pipe protruding from the flat square of flashing and slide the entire section off the vent pipe.

Lift the upper layer of shingles and slide the replacement sheet lead or copper flashing over the vent pipe. Tuck the upward angled half of the flat section under the layer of shingles above the vent pipe.

Secure the flashing to the roof with galvanized roofing nails. Hammer one nail through each corner, and another through the center of the flashing on all sides, about half an inch in from the edge.

Seal all nail heads with a dab of bitumen roofing sealant.

Secure the row upper tabs to the roof by applying a layer of sealant under the tabs and across the flashing; this will prevent the lower edges from peeling back during periods of high wind.

Install a waterproof UV-resistant rubber roof vent boot over the vent pipe. Stretch the flexible neck and slide the boot all the way down the vent pipe until it rests snugly against the roof.