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August 7, 2008

leak detection

we seem a leak in our sewer line underneath our recently renovated bathroom. We want to minimize damage. Do leak detection services work? Any recommendations? Advice?

Posted by annon at 11:36 PM | Comments (5)
Categories: Plumbing

Comments

the most common detectors are either a box shaped like a pack of cigarettes with 4 screws on one side. If any 2 of those screws become shorted (water is conductive) it goes off. These can be installed with the screws facing up which means you need to have a 1/2" of water before you get notification. Or you can put it in screws down which may make it prone to false alarms if you have a damp basement. There are some other designs out there but they all work on very similar principles. Typically these are tied to your security system so that the central station would be able to notify you if you aren't at home.

Posted by: Bklyn Fire Alarm Guy at August 8, 2008 8:52 AM

Thanks for your response bklyn fire alarm guy. I guess my original post wasn't clear. We actually do have a leak, as evidenced by the sewage that flows into our kitchen when we flush toilet or take shower. But we want to identify the location of the leak without tearing up the entire relatively new bathroom. I know some plumbers advertise cameras, would such a device be able to identify the location?

Posted by: annon at August 8, 2008 11:05 AM

Call a plumbing company and ask them if they have a camera they can snake through. I know roto-rooter has the service available. They run a camera attached to a line and have a small LCD screen. As the line goes through it measures the distance from point of entry. At the end they give you a VHS with the recorded footage. The cost is around $250 but well worth it if the problem is complicated.

Posted by: landlord at August 8, 2008 11:53 AM

I think you can probably do a little deductive reasoning to help you narrow it down.

- Run the shower with the drain covered. If it doesn't leak, it's in the drain system, not the supply system (seems like that's the case since both shower and toilet cause leak, and you state it's during flushing the toilet, not filling)

- If it's in the drain system, and both the toilet and the shower leak, then you can look downstream of whichever device is closest to the main sewerline. In other words, if the shower is upstream of the toilet, but you get a leak from both sources, the leak is at or downstream of the toilet. Vice versa for shower. It's possible to be in between the two, but highly unlikely if the rest of the DWV system is installed correctly.

- Where does the sink drain? If it's downstream of the other two, and it doesn't leak when used, then the leak is between the sink and the other two sources. If the sink is on a different drain line, then it wouldn't be leaking for the same reason.

- Where is the water coming out in the kitchen? If it's already damaged the sheetrock in the kitchen, pull that out to see if you can see the leak. Either way, you're probably going to replace the sheetrock unless the leak is fairly minor and recent. Sometimes leaks come out and follow a beam to a different exit point, or follow electrical conduit to exit in a fixture. It seems to me that if you've already finished the bathroom (assuming tile on floors and wall), you'll want to try to access the drain from below. The kitchen ceiling is easier to patch than the tile floor.

Does that help at all?
Dan B

Posted by: dbarufaldi at August 8, 2008 2:41 PM

for those interested:

1) we dug through tile in new bath and through floor of bathroom.
2) the water was leaking from a pipe in between the kitchen (upstream) and bath fixtures (downstream)
3) we found two 3-4 inch holes in pipe
4) water back flows from toilet and shower to point of leak, so it would seem the drainage system is not installed correctly.

We'd rather not dig up the entire floor to the main line. Any thoughts on ignoring the back flow problem? Is the only risk a broken pipe in 60 years from standing water?

Posted by: annon at August 11, 2008 5:46 PM

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