How To Install Vent Pipe Flashing On Flat Existing Roof

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.

How to install vent pipe flashing on flat existing roof.

This great video presentation shows you how to seal a pipe on a flat roof to avoid water ingress and completely waterproof a flat roofing installation. Put one nail in the bottom edge with a dab of caulk under it to seal the. 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. Use one roofing nail in each corner of the flashing to secure it to the roof.

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. To make the installation easier you can turn the flashing as you lower it in place. I ve used this repair on several roofs over the years. See other blogs for a proprietary vent flashing repair kit and a repair using a boot flashing with the roof pan trimmed off.

Finally reattach all shingles removed in the process. Hammer the nails into the top and sides of the flashing. Slide the new flashing over the vent pipe and under the shingles above the pipe. 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.

Install flashing on existing roof to extend the lifespan of your roof. Roofing nails per side photo 2. Add a large bead of caulk in a half moon shape around the flashing and put the shingles back in place.