Replace Faulty Chimney Flashing to Stop a Leak
LESLIE: Alright. Next up, we’ve got Sue who’s dealing with a leaky roof. Tell us about it.
SUE: Hi, Tom and Leslie. Thanks so much for taking my call.
We have a leak in our bedroom. And I live in – we live in a patio home which – you know, a two-story patio home. It’s got just a simple peak roof. The chimney is in the center of the house; it’s not on an outside wall. And the chimney stack has a wooden structure built around the stack itself.
SUE: And my husband was up there last year and thought he had resolved the problem. Whenever we have a very hard, driving rain – and he says mainly, when it comes out at the southeast – south or southeast – we get excessive leaking in our bedroom.
SUE: The popcorn ceiling’s falling down.
TOM: Oh, boy.
SUE: It’s pretty bad, yeah.
And so he was up there last year and he said that he tarred around the flashing or underneath the flashing?
SUE: But it’s obviously not resolved the problem. So we’re not sure if the leak is emanating from the bottom of this wooden structure.
SUE: The roof itself is only eight years old; it’s in very, very good condition. The chimney is directly above our bedroom, so we really suspect that’s where it’s coming from.
TOM: OK. So the chimney pierces the roof above your bedroom? Is that correct, Sue?
TOM: OK. And by virtue of the fact that you’re telling me your husband is tarring flashing, that, in and of itself, tells me that the flashing was probably not put on correctly initially. Because chimney flashing shouldn’t be relying on tar to remain leak-free.
LESLIE: Mm-hmm. And tar really isn’t the answer.
TOM: Right. When properly installed, flashing is a two-piece operation. You have a base flashing and a counter flashing. The base flashing goes in between the roof shingles and lays up against the side of the chimney. The counter flashing gets notched into the side of the chimney and folded over the base flashing. And together, it creates a seam that can expand and contract with the roof and seal out water, regardless of direction.
So, couple of things that you can do. You could just decide to have the chimney flashing properly replaced. And let me just tell you that you have to be very specific about finding a roofer that can do this properly.
TOM: You can’t leave this up to chance, OK?
TOM: You don’t want to hire another guy to go up there with a bucket of tar. You need a real pro that can properly assemble flashing.
TOM: The other thing that you could do is – is there some amount of roof that is above this that sort of drains into the chimney?
SUE: As I said, it’s a patio home and it’s got a simple peak roof. The chimney itself is built on the back side of the slope, just on the other side of the peak.
TOM: Right. If I was a drop of water and I was running down towards your chimney from the peak, how far would I have to travel? Like a foot, 10 feet, 20 feet, what?
SUE: Oh, no, no, no. I’m looking at maybe 3 feet from the peak?
TOM: OK. Alright. Because if it was farther down, I was going to tell you that you could install what’s called a diverter, which catches some of that water, runs it around the chimney so it doesn’t hit the back end of it.
TOM: But if it’s that close, you don’t have to worry about that.
So, what I think you probably need to do is to replace the flashing, if it appears that it’s coming through the chimney. Now, this is a masonry chimney?
SUE: No. It’s a chimney stack: just a metal chimney …
TOM: A metal chimney? OK.
SUE: It comes up and it’s surrounded by this wooden structure that’s been built around it.
TOM: Is he sealing against the wooden structure?
SUE: To be honest with you, I haven’t been on the roof and he’s not here to answer that question but I think so.
TOM: OK. OK. So then, he’s kind of wasting his tar, OK?
SUE: OK, OK.
TOM: Because that’s just for show. If this is a – it’s called a “chimney chase.” If you have a chase around a metal vent type of chimney, then what you have to do is remove the chase and reflash the metal chimney where it meets the roof. And then you can replace the chase.
SUE: OK. And he wondered about that, if it was coming from the top of the chimney stack and down into that wooden structure, not along the edges of the wooden structure itself.
TOM: Maybe it’s the train going by your house that keeps rattling the roof leak.
SUE: Sorry. I tried to step in the garage so you wouldn’t hear that.
TOM: Well, listen, the chimney chase itself is decorative. So I would take that out of the equation and get down to the metal vent itself. Seal and flash that and I think that’s going to solve your problem. If he’s just caulking around the chimney chase, water’s going to roll right through that and keep coming on in.
SUE: OK. And he considers himself a jack-of-all-trades, master of none but he is pretty handy.
SUE: But you suggest that this is not something that he …
TOM: Well, I would suggest that if he’s caulking the wooden chase and leaving the metal vent pipe, that perhaps a chimney repair is not one of the trades that he is the jack of.
SUE: OK. And if he were here, he’d probably correct me. I’m not certain what he did. I’m a little afraid to get up on the roof myself.
SUE: But alright, I will pass that information on to him. And I guess we’ll be calling a roofer.
TOM: Alright, Sue. Good luck with that project. Thanks so much for calling us at 888-MONEY-PIT.