Leaks in pipe under foundation

Al Letellier_9

How about PEX ???

Fred Van Deusen

Leaks in heating pipe under foundation

A number of years ago we had a leak in the black heating return pipe that goes under our slab foundation. It was very difficult and expensive to re-route the return, so we installed 3/4" copper inside the 1 inch black pipe. That worked for a number of years but now it's leaking again. What would you recommend we use to replace the copper pipe, assuming we can get it out? It will need to fit within the 1 inch pipe.

George_10

After you fix this leak, you would be well to consider

cleaning and treating this system. The leaks are coming due to pipe corrosion. Other metals within this system are also doing the same.

Repair is much more expensive than prevention.

Bob Sweet

Fred

Are you on well water? What type of emitters are you using, radiant, baseboard etc.?? How long ago was the re-route done?
Was a pressure test done after the repair?

Christian Egli

Settling occurs inevitably

Do you have any cracks in your concrete floor?

It could be possible that different sides of the crack in the floor are moving in different directions. This would be a very slight motion, one that follows the seasons or maybe the water table level. It's the sort of thing that propagates cracks right through a home.

This being the case, your floor could resemble a butterfly in flight, both wings being the two sides of the concrete, hinging about the crack.

Any metal pipe crossing the crack will not last, because metal only flexes so often, then it breaks.

I have seen this problem several times with in floor electrical conduits. Mind you, electrical conduit is not as solid as black pipe. It is a problem that also comes up when underground pipes cross a road or a parking lot.

Materials that can take the flexion are either PEX, rubber or (polyethylene, not for hot stuff).