Underslab leak

[gregs]

I think I have determined that I have an under slab water leak on a hot water line that feeds the master bathroom which is the furthest water connection from the water heater. I suspect that the same line also feeds the kitchen as it is between the water heater and the master but dont know that for sure. About a week ago I heard the faint sound of water running (like when you can hear an outside spigot on from inside the house) and it seemed loudest at one of the vanity sinks. But I can also hear it at the shower valve and the other sink, but it doesnt seem to be as loud. So I turned different things off until I narrowed it down to turning off the cold water side of the water heater stopped the sound. I have been checking walls and floors and could not find a leak inside the house any where. The house is a split level with concrete foundation and stud walls that is covered with brick. The grade is such that the front of the house where I think the plumbing should be is about 24" above the ground, so the foundation is covered with brick as well across the front. I have found an area in the brick where it appears that certain bricks are wet looking in a somewhat stair stepped pattern. It is located between the kitchen and bathroom. So I am trying to determine if the leak is in that area would I be able to hear it at the bathroom faucet which is about 15' away from that area? I dont hear anything at the kitchen faucet which is actually closer to the area. Or would that indicate that there is a separate leak closer to the bathroom faucet?

 

[Terry]

There are companies with listening devices that help locate underground leaks. Sometimes working with a moisture meter helps too. At least you have narrowed it down to the hot water line. What decade was the home built? Is it copper or galvanized?

 

[Sponsor]

 

[gregs]

The house was built in 1981 and has copper plumbing. At least I can shut it off and stop the leak until I figure it out.

 

[gregs]

I think the foundation uses a short stem wall made with concrete block on top of a footer. When they do the rough plumbing, do they typically knock a hole thru the block and pull the piping up thru an open cell? The kitchen sink and bathroom vanities are on exterior walls.