Roof Causing Vent Leaks?

Find out if your roof can be causing a leak in your bathroom ventilation system. Try using pipe flashing to seal the area around the vent and prevent more leakage.

LESLIE: Dolly in Florida has a leaky bathroom vent. What can we do for you? Tell us what’s going on.

DOLLY: Yep, sometimes it leaks and sometimes it doesn’t when it rains.

TOM: OK.

DOLLY: Like today we had really a downpour and wind blowing and everything and it didn’t leak today, so I don’t know what’s going on. It’s like a round vent with a cap over the top.

TOM: Dolly, is this an asphalt-shingle roof or a metal roof?

DOLLY: It’s a metal roof.

TOM: OK, what I think is happening is I think that you probably don’t have the right type of flashing around where this comes through the metal roof. And, as a result, whoever put this in probably just tried to use some caulk or some other type of roof cement or something of that to seal that space and that’s going to be just destined for trouble; because of the expansion and contraction, it’s going to crack.

There is a product that’s called Dektite – D-e-k-t-i-t-e – and this is a design for a pipe flashing. It works for plumbing, for heating and for exhaust vents. And it basically goes around that round pipe where it comes through the roof and it seals to the roof and it seals to the pipe and absolutely prevents any water from getting in there.

You might want to take a look at a building supply website like ITW Buildex is one that has this sort of industrial commercial supply. But that’s the kind of product. And I hate to put you in charge of this but this is something that a roofer should know to do. You need to have a flashing boot around this and they didn’t put one in and that’s why it’s leaking.

DOLLY: OK, thank you very much.

TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.