Fixing a Leaky Skylight
LESLIE: Adam in Rhode Island is on the line with a leaky skylight. What’s going on?
ADAM: I have a bay window in my bedroom and it’s below a skylight. And for a while, it started to create those brown stains on my ceiling but for the most part, the biggest problem was there’s a leak in the bay window. So, my father and I went up there. We put a new flashing kit on the skylight and it seemed to help the problem, but it did not eliminate the problem.
And I had a contractor friend over who took a look at it, as well, and he noticed that if you go out on the outside, the bay window abuts the gutter where the gutter attaches to the roof above it. And it’s his opinion that there should be, perhaps, some 6- to 8-inch gap there between where the gutter meets the house and where the bay window starts. So it’s his opinion that the bay window might have been improperly installed.
TOM: So, it sounds like the bay window is up too high? Is that what you’re saying? So it basically goes right up under the gutter?
ADAM: Right. It certainly – there’s certainly no separation between the soffit but there’s also no separation from where the gutter meets the house, either.
TOM: Alright. And does the bay window have its own roof on it? Or is the roof sort of built into the soffit structure?
ADAM: No. It’s under the overhang.
TOM: Oh, it is under the overhang. OK. Mm-hmm. Is it possible that the gutter is overfilling and perhaps the water is backing up through the gutter, getting into the soffit and running into the bay?
ADAM: I thought that at one point. And I have gone up and checked the gutters and they are clean.
TOM: OK. And where this is on the roof, is there sort of a long stretch of roof that goes down before this – before it hits the skylight?
ADAM: Yeah. I guess so. Maybe 10 or 15 feet.
TOM: So I’m going to give a trick of the trade and this might solve it. You might be getting so much water against that skylight that it’s just sort of forcing its way in. One thing you might want to do is to try to put a diverter on the roof right above the skylight. And this – see if this works. It’s really easy to do and so there’s kind of no reason not to try it.
But you make a – you take a piece of aluminum in the shape of an L and you basically attach it to the roof. And you essentially want to intercept that flow of water down the roof and have it run around the skylight and around the bay window. So you’re slowing the volume of water that’s coming down that roof, running full steam towards that skylight and that bay-window area, and running it around that space. And all you’ve got to do is tack that onto the roofing shingles, put some silicone caulk to help seal the edge and see what happens.
ADAM: So you caulk the edge of the L with silicone. And how do you affix the aluminum to the roof?
TOM: Yeah, you could simply nail through the shingle and with a roofing nail.
TOM: Because you’re – well, the caulk will help seal it. And basically you’re capturing that water as it’s running down the roof. And it’s sort of running right around that skylight/bay-window roof combination and then off to the gutter.
ADAM: Alright. Sounds good. I’m willing to try it.