leak in slab foundation

[Dave Ddd]

my house in built on a slab foundation. in the utility room of the house the water pipes (hot and cold) go into the slab then come up through the slab in the kitchen and for the washer.about 15 months ago came home and found water all over the hall. looked where the water pipes go through the slab and there was a bad leak somewhere.plumber came out turned the water off said he would be back the next morning to fix it. said the water heater would have to come out because you could not get to the pipes to repair them because the water heater was in front of them. when be came back the next day it was mostly dried up. he turned on the water to get an idea which pipe was leaking and there was no leak. he waited ran water through out the house no leak. it was not the water heater it was not wet on the bottom or the sides of it. after 15 months no leaks there was a lot of water because i had to rent a carpet machine to get all the water out of the carpet. no one can figure out where the leak may have been and why it stopped. am afraid it will happen again. have lived in the house over 30 years. the water heater relief valve goes to the outside of the house so i know that was not it. anyone have any ideas. or ever heard of anything like this? thanks DAVE

[jim donovan]

a local stoppage ,maybe w/m drain backed up.sometimes they do clear on there own.i should ask first did you leave the house with the w/m running?

[Blackbeard]

First, turn off EVERYTHING in your house that uses water. Go take a read on your meter. Write it down. Now hang out on the back porch and smoke a few cigarettes. Walk out to the meter. If the numbers have changed at all, that water has to be going somewhere...so you've got a leak. If the meter hasn't moved at all, it's very likely there is no leak.

If you want to be absolutely sure, take a drill and drill a hole into your foundation (below the poured slab). If the gravel layer between your slab is saturated with water, the water will spill out of the pilot hole you drill. If you drill a hole and water starts spilling out, get that water tested immediately to determine if the water is sewage or stale water from your supply line.

If you have something going on under slab, you might find someone who does tunneling. I've only met one guy over the years that was crazy enough to tunnel under a slab. But you may have someone in your area who can fix a slab leak without breaking the slab.

If you have to break into the slab, the cheap way out is to hire a company that does concrete drilling and boring and have them break up the slab. it's cheaper than paying your plumber to ride a jackhammer. Pay your plumber to do plumbing work. Have general laborers break and dig and wheel concrete and dirt outside the structure. and have a concrete man patch your floor. Don't know about everyone else around here, but when I have to break and dig and haul and backfill and patch, I'm going to charge you a small fortune.