House (on a slab) water leak, no water to be found?

I need help from the beeb experts. We live in a 3 bed 2 bath ranch built on a slab in 1974. Starting this morning I can hear water running through pipes but there are no Wet floors or water around the 2 outside faucets. I am worried we have water leaking from copper pipes in the foundation and into the soil below. I did just notice a warm spot on our tile kitchen floor but there is no water to be found. Any suggestions on where to start this process? I have already checked to be sure the toilets are not running or leaking and I have shut off the water valve for the whole house. It has been 15 to 40 degrees here weather wise but I highly doubt any problems from freezing.

 

A leak detector service can pinpoint where the leak is.
A house pushing 50 years old is pretty typical for leaky pipes.
Even with copper, electrogalvanic reaction eats away at metal. Then, there's settling in the slab.

It's likely you will be better off rerouting the service line, unless you're talking about radiant floor heat

 

Likely a pin hole in the hot water line as Big T suggested. It could take a while to saturate the soil and slab before you get water coming up through the floor. I had a client with a similar issue and the void below the slab would hold about 20 gallons of water before it started coming up through the floor.
Call a leak detection company to verify and pinpoint.
Depending on your insurance policy this is also something that may justify a claim. If you have any questions about that, feel free to PM me. I'm a public adjuster in Florida, so I represent many homeowners in your situation.

 

Had it in California. Just repipe above ceiling. That’s what everyone out here does. If the floors warm you’ve gotta leak. It wasn’t all that expensive if you have access to the attic.

 

My brother just had something like this.
His house has partial basement and concrete slab. An iron water pipe layed down under the slab cracked and started leaking.
It was a big problem and I sincerely hope yours isn't like this.
He had called some professionals and they all agreed it was the pipe under the slab. This seems to be happening in other homes in his area that were built this way.
He got a handheld metal detector to find the pipe. Cleared out his living room, kitchen and dining room.
Jackhammers inside your house. Piles of dirt inside your house. It sucked for them.
It was costly and tough to endure.

I hope you don't have a situation like that.

 

is your meter showing any signs of consumption with the water turned on?
Ive seen plumbers do leak detection and its similar to leakdown testing an engine.
Good news is pex is relatively easy to work with for replumbs...

 

The Uponor version of PEX is the best for going through the attic in colder climates.

 

There is no need to pinpoint the leak. Copper degrades somewhat evenly. Your plumbing is probably eggshells by now. This is just the first point to fail. Replumb with PEX and move on.

 

Many year ago i lived in an older apartment. One Friday afternoon i get a call from the manager....The water pipe from the slab into the apartment next door broke right at the slab due to age + being in concrete. It flooded that apt and mine.

I get home to the whole floor being soaked...some of my boxes/stuff soaked. They sent in water crew who sucked up the water, pulled up carpet to dry it, etc. I had to go stay with relatives for the weekend.

Metal pipes IN slabs suck and will fail. I agree with the others. Lok into re-routing the water thru the walls/attic and use Uponor.
Any chance insurance would cover some of this?

Good luck.

 

start here for sure .. water meter should have leak detection meter swirling if you have everything shut off inside, but water is leaking somewhere.

 

Check the meter. Should be a little red dial or needle spinning indicating water moving. If you’re not using water and that meter is spinning, it’s a leak.

 

As others have said, just repipe and move on. Plenty of companies who specialize in it, with some able to do it in a day, depending on the size/complexity of the house.

Uponor make a coiled PEX that’s flexible and easily pulled through walls. They offer it insulated, as well.