We are remodeling our master bathroom. We changed out the tub for a shower. The drain and the supply are all new, and we used a rubber "T" to connect the existing vent with the new drain and existing sewer. Now we have a leak from the existing vent in the roof. Upon examination it looks like the vent pipe only penetrates the roof by four inches and then the flashing above stands up 6 inches, meaning that fold over part of the flashing never meets the actual vent pipe. Do we "A" cut the flashing to come down lower and meet the pipe, or "B" replace the pipe with a longer PVC pipe to make the joint, or "C" switch from the lead flashing to a rubber boot sealing directly to the outside of the pipe.
Thanks

All three of the options are OK, and if I were you, if the flashing is made of lead, I would cut it off to about one inch above the pipe and then bend the lead down into the pipe.

I agree with Letmetellu, 4" is a little short but will work just fine. vWe make our vents 6" and cut the lead flashing back and fold it over. Good luck, Tom

Go to the attic, cut the short vent 12" below the roof, glue on top of the vent new coupling, cut 24" long new section of vent, reinsert through same flashing and glue to the coupling.

Go on the roof and caulk around where pipe penetrates flashing.

Don't cut the flashing. If you cut it lower, you will enlarge its opening. Now, 2" pipe will be too loose in its opening.

Milo, You guys poke your vents up 12 inches over the roof line? Why? Are you in snow country where the vents are liable to be covered by the next snowfall? 12" vents just gotta look funky poking outta there. Is there a reason for this or is this just another "off the wall" code by UPC?
Don't cut the flashing. If you cut it lower, you will enlarge its opening. Now, 2" pipe will be too loose in its opening. Say what? Doin't cut a lead flashing back. We have always rran our vents out 6" over the roof line and cut the lead flashing back a few inches above the top to fold over. What ever made you think that lead flashings were tapered so if you cut them back they grew larger? Regards, Tom

Milo, You guys poke your vents up 12 inches over the roof line? Why? Are you in snow country where the vents are lible to be covered by the next snowfall? 12" vents just gotta look funky poking outta there. Is there a reason for this or is this just another "off the wall" code by UPC? Say what? Doin't cut a lead flashing back. We have always rran our vents out 6" over the roof line and cut the lead flashing back a few inches above the top to fold over. What ever made you think that lead flashings were tapered so if you cut them back they grew larger? Regards, Tom

Hey, Tom, you have been long playing golf for way too many years now ! :D Tom, we don't use lead flashings. Never. In fact, you cannot get even close to anybody's house in So. California with any material that contains lead. Period. Lead is a 4-letter word here.

We use sheet-metal flashings. They are tapered. If you cut it off at the top, than it will be too big for the size of pipe it is made for. Home Depot sells plastic/rubber flashings. Unfortunately, they are not allowed by our Plumbing Code.

I don't know what's the reasoning behind 12" roof vents above the roof, but that's how they want it. We just comply. Many people come back and cut them lower. Yes, it looks funny to see vents sticking up on the roof - but that's a sight we just have to get used to. :D