How to Repair a Roof Flashing Boot (in a Flash)
You’ve seen this before; a plumbing vent flashing that is completely deteriorated from UV damage. While such a flashing is easy to replace while laying new shingles, it is a whole different challenge with old, dry, sealed down shingles where removing the flashing will damage most or all of the surrounding shingles.
The Hard Way
In the past I’ve always spent way too much time extricating the entire flashing from the layers of existing shingles in hopes that the few extra shingles the homeowner had saved will be enough to patch and weave back into the roofing around it.
A Better Way
Faced with this scenario the other day, a better idea hit me: instead of removing the entire flashing, it would be much simpler to replace just the failed part: the rubber gasket. Since the rubber boot is crimped into a channel in the galvanized metal flashing it didn’t seem feasible to un-crimp the old boot out, un-crimp a new boot out of a new flashing and then re-crimp the new boot into the old flashing, so I did the next best thing. With an identical new flashing from the local home center in hand, I carefully cut out the humped center portion out of it. After cutting out the scraps of the old UV damaged boot from the existing flashing and applying a generous bead of urethane sealant, I simply slipped the new boot over the vent pipe and down onto the old flashing and secured it with a couple of galvanized self-drilling screws. It was never so easy to do a callback-free repair of what is normally a very unpleasant task.
I’d sure like to hear from anyone else who finds this method helpful.
Vent flashing with serious UV damage
New replacement flashing with center cut out
New flashing ready for installation
Flashing repaired... in a flash