Fix a Leaking Sewer Pipe

LESLIE: Koi (sp) in Alabama, welcome to The Money Pit. Tell us what’s happening at your house?

KOI (sp): Well, I purchased an old house that has an above-ground, cast-iron sewer pipe. It has a leak and the ground underneath is wet. It’s not a bad leak. But is there any way to patch that; cover it with rubber or something and – rather than having to cut a section of the pipe out?

TOM: Well, cast-iron pipes generally don’t leak; although sometimes it looks like they do. Now, are you absolutely sure that water is getting out of this? And I’ll tell you why they don’t leak. Because typically the water runs one way down the pipe and it doesn’t leak unless there’s a blockage in the pipe that causes the water to back up. Now, having said that, many times around the joints, around the pipe joints, it looks wet; it looks leaky. But that’s not a leak. What that is is a material called oakum which is oil-based that is used to make the gasket where these pipes come together. Sometimes that oil will leach out and make the pipe look wet but it’s not really a leak.

KOI (sp): Well the ground underneath is wet under that spot.

TOM: So, this is going – but you said it goes above ground?

KOI (sp): Yes, it’s above ground.

TOM: So it goes above ground from the basement? Or where?

KOI (sp): It’s a large crawlspace. It’s about a four-foot crawlspace and it’s about midway between the ground and the floor.

TOM: And the ground underneath it is wet …

KOI (sp): Yes.

TOM: … and do you see a place in the pipe where the water is leaking out?

KOI (sp): I haven’t found where it’s leaking out but I put my finger there and there’s water on it in between the joints.

TOM: Well, here’s what I would do. I would run some water through those pipes and see if you can pinpoint exactly where the leak is. If it’s in the joints, those joints can be repacked with the material called oakum and that will stop the leak. But I will say that it’s very infrequent for those leaks to occur.

KOI (sp): Yes, it’s a very old house; about in the 1920s, late 20s.

TOM: Is it a cast iron pipe?

KOI (sp): Yes, it’s cast iron pipe.

TOM: OK. Well, it doesn’t go bad when it’s cast iron. It just needs some maintenance.

KOI (sp): OK, well I’ll run the water through there and check and see if I can determine where it’s coming out.

TOM: That’s the first step.

Koi (sp), thanks so much for calling us at 888-MONEY-PIT.

KOI (sp): OK, thank you.