How To Install Vent Pipe Flashing On Flat Existing Roof

Use roofing nails to install the l shaped flashing flush with the roof and wall then cover it with roofing cement and reattach the roofer s felt.

How to install vent pipe flashing on flat existing roof.

The neck of the flashing should fit snugly around the pipe. Use one roofing nail in each corner of the flashing to secure it to the roof. Roofing nails per side photo 2. See other blogs for a proprietary vent flashing repair kit and a repair using a boot flashing with the roof pan trimmed off.

Install flashing on existing roof to extend the lifespan of your roof. Center the pipe in the flashing and push the flexible front corners up or down so that the flashing pipe is parallel to the vent pipe. Rubber vent flashing automatically adjusts to any pitch lift the vent enough to spread caulk under the sides but not the bottom edge then nail with three 1 1 4 in. Finally reattach all shingles removed in the process.

The flashing should be installed under the top and side shingles but it should be laid above the shingles that are below the vent pipe. Now that the old flashing is gone you can slide the new flashing over the pipe vent and maneuver it under the shingles above the pipe. Hammer the nails into the top and sides of the flashing. I ve used this repair on several roofs over the years.

To make the installation easier you can turn the flashing as you lower it in place. Slide the new flashing over the vent pipe and under the shingles above the pipe. In simplest terms a new vent pipe boot flashing is slid over the top of the existing one and the top edge of the pan is lapped beneath the overlying shingle course.