Locate the Source of Leak Behind a Kitchen Wall
Morgan in Maryland is listening in on WJFK, Free FM. What’s going on at your house and how can we help?
MORGAN: Well, I’ve got a bit of a leak behind the wall and I’m trying to figure out where it is before I pull out the entire kitchen counter and sink.
TOM: Oh, boy.
LESLIE: (overlapping voices) Ooh, that’s a mess.
MORGAN: But it’s not generating from the sink or below the sink. It’s in the wall.
TOM: And is it leaking all the time or does it only leak sometimes?
MORGAN: Only sometimes and I don’t know if it’s a waste line. I’m assuming it’s not a feed line but it’s probably a waste line; although it’s hard to tell because it’s not substantial enough.
TOM: So where are you seeing the leak?
MORGAN: I have evidence of a leak at the base of the kitchen counter and above it and discoloration of the wallpaper around the window above the sink. So it’s got to be generating from slightly above the window line.
TOM: Well, it sounds to me like it might be a leak in the window, then. Why do think it’s a plumbing leak?
MORGAN: It’s far enough away from the window. It’s nearly two feet away from the window. So – and it would be – it would have to be a leak directly across, which wouldn’t – you know, I’m fairly certain it’s a waste line or a feed line.
TOM: Let me ask you this, Morgan. Have you taken a look at the vent pipe in the roof? Is the vent pipe in the roof above the kitchen?
MORGAN: Actually, there is one directly above that that goes up, but it’s too high for me to go up. I’d have to have a professional go up on the roof to …
TOM: OK. That’s where I would start. That’s where I would start. Chances are it could simply be the flashing around the vent pipe itself.
TOM: Because there’s a little boot, like a rubber boot; sort of like a gasket that goes on top of that pipe and under the shingles. And very often, that will crack and dry out. It actually happens fairly frequently. And if that gasket is not working properly, you can get water that’s going – running down, sort of hugging the pipe and then leaking out into the wall where you’re seeing it.
MORGAN: Now, this is an older home. It’s about 60 years old. And so the walls are pretty substantial. Is there any way – is there any sort of device that detects water that can give me sort of a – somewhat of a view before I do the cleanup and repair?
TOM: Yes, it’s called a moisture meter and there’s two types of moisture meter; there’s destructive and non-destructive. And the difference is destructive isn’t really that destructive. It just has sort of like two pins that sort of stick in the wall and measure the moisture in the wall. A non-destructive sort of shoots a wave through the wall and determines it that way.
A home inspector is the kind of professional that would have those tools handy. And that’s another option for you is to call a home inspector in to do a leak investigation. And perhaps with that person’s skills and they’re specialized tools, they could narrow this down.
But it may not be that complicated. If there’s a vent pipe right above this and you have a leak, it’s very, very common for that to be the source. So I would start with that. Perhaps you can get someone to check that roof for you. And then if that doesn’t work out, you could call a home inspector in.
MORGAN: Great. Thank you very much.
TOM: You’re welcome. To find one in your area, there’s a website for the American Society of Home Inspectors. It’s a not-for-profit professional society. It’s at ASHI – A-S-H-I – .org.
MORGAN: H-I. Yeah, I’ve actually been there.
TOM: Yeah, great. Use that. Put in your zip code. You’ll find a list of folks in your area.
MORGAN: Thank you so much.
TOM: You’re welcome. Thanks so much for calling us at 888-MONEY-PIT.