Diagnose Cause of a Leaking Ceiling

Learn how to diagnose the cause of a leaking ceiling. Find out how to tell if it's a condensation leak and how to repair a crack in your ceiling.

LESLIE: Debbie in Indiana needs some help with a leaky ceiling. Tell us what’s going on and how much water is coming in.

DEBBIE: It’s not a lot of water. It’s like drips of water, but it’s from my ceiling, which I have a small, maybe six-inch crack in it; in the plaster area. And I’m wondering if like the heat from the house, when it goes up to the attic is causing moisture in the attic and then it thaws out and comes right back down; if that’s what it is. Because we just had a new ceiling – or not a new ceiling – a new roof put on it like three years ago and around the stink pipe or whatever, there’s a new boot on it which my grandson put tar around it and everything so I know it’s not the roof. But …

TOM: Well, does it leak consistent with rainfall, Debbie?

DEBBIE: No, not too much. It’s like in the winter time, no. No. You know, when it gets cold and then it’ll like – it’ll warm up and then all of a sudden it comes down again. So, I was wondering – they went up there last year and the insulation was wet. So they …

TOM: Hmm. Well, obviously – it sounds to me like there’s a leak there somewhere.

DEBBIE: In the ceiling?

TOM: And I don’t – if you told me that this was leaking in the summertime and you had ducts up there I might recommend that you take a look at the condensation that could be forming on those ducts. But that’s not …

LESLIE: Is it possible that a bathroom vent fan would be vented into the attic and that could produce enough moisture?

TOM: Not likely. I don’t think so. I think you’ve got a roof leak. And the thing is about roof leaks is that you have to remember that they can leak and then run over 10, 15 feet before they show up.

DEBBIE: OK.

TOM: So I think you’ve got to get up there and take a real careful look with a real strong flashlight the next time you get these conditions.

DEBBIE: OK. So I need …

TOM: Because I don’t think this is happening by condensation. I think it’s, pure and simple, a roof leak.

DEBBIE: OK. That’s what I was wondering because I didn’t want to put a lot of money into it and then – or have somebody tell me, “No, it’s not that,” and you know.

TOM: No, I think that’s what’s going on and Debbie, listen, when you get it fixed then you can use some fiberglass tape across that crack and a couple of layers of spackle; then prime it and paint the whole ceiling and you’ll be good to go.

Debbie, thanks so much for calling us at 888-MONEY-PIT.