Leak in pipe is barely above the concrete floor. If try to cut and solder will be too low. Any suggestions? Too close to concrete for SharkBite connections.

  • It was the slab that is the foundation.
    – Lmdschool
    Commented Jul 10, 2019 at 3:09
  • 1
    The slab isn't the foundation. A foundation consists of footings and walls. A slab is mostly just a floor.
    – isherwood
    Commented Jul 10, 2019 at 12:58

3 Answers 3


You can solder a copper repair coupler over the hole. It's basically just like a sleeve. You don't have to cut the pipe near the concrete.

Sand and flux the bottom inch of the copper pipe above the concrete. Cut off the copper pipe maybe 1 foot higher than the concrete, and drop a copper repair coupler that doesn't have an internal stop onto the pipe and slide it down to the top of the concrete.

Next shorten the copper pipe enough to add a second copper coupler that does have internal stops. Sand and flux the pipe. Add the coupler, solder both couplers at the same time.

The first coupler seals the leak, and the second coupler is needed to repair the pipe after cutting it.

Make sure to sand and flux the inside of the couplers too.

  • 1
    Be sure to use MAPP gas, if this is the main, turn it off of course, but make sure it is EMPTY at least a few inches or more below your solder location (syphon it if you have to). Make sure upstream is open, cut, detached or the like and that you keep it open (preferrably as much and as close to the repair as possible.
    – noybman
    Commented Jul 9, 2019 at 5:10
  • 2
    What if the leak is only 1/4" above the foundation? Is this still a good approach? Will you be able to apply enough heat to the pipe in the concrete foundation?
    – JPhi1618
    Commented Jul 9, 2019 at 6:13
  • 1
    @JPhi1618 I think it'll work because the copper pipe embedded in the concrete is continuous through the coupler, and not two separate pipes. The heat added to the coupler and top of the pipe will easily transfer through to the part of the copper pipe below the coupler and under the concrete. Copper has an extremely high thermal conductivity, and the concrete will act as an insulator to retain the heat in the copper since concrete is an extremely poor thermal conductor.
    – Dotes
    Commented Jul 9, 2019 at 18:20
  • 1
    Note that the second coupler (with internal stops) can be replaced by a push-fit or compression fitting if the OP doesn't fancy soldering two fittings at once. Alternatively I have managed to use a wet rag to stop heat from soldering one fitting melting the solder in another. Commented Jul 9, 2019 at 19:25

The coupler idea in another answer is a good one.

If the leak is too close to the concrete surface so as to create an uncertain solder joint you can consider chipping out the concrete in a narrow ring around the pipe. This could easily be 10 to 12 mm deep to allow the coupler to slide more past the leak.

If you decide to do this you must really clean all concrete that has adhered to the pipe and shine up the copper well so that the flux and solder will flow and adhere to the pipe and coupler.

  • True, but at the same time, when cleaning it, care should be taken not to go hog wild or else flat spots will develop promoting a leak. Of course flux and good solder technique has a high success rate, but the reason I add this is because solder technique is ability + art.... in other words, it may be tricky.
    – noybman
    Commented Jul 10, 2019 at 4:57
  • If I were going to the route of making better access, I would go back to thinking about a compression fitting first. Commented Jul 10, 2019 at 13:02
  • The procedure did work but for some reason I have half the water pressure than before the leak or even with the leak.
    – Lmdschool
    Commented Jul 12, 2019 at 5:11

Were it my house I'd assume that the corrosion goes beyond what's visible. I'd rent or borrow a concrete saw and cut out a 12" square of concrete around the pipe. I'd then make suitable repairs with common copper parts (or PEX) and simply fill the opening with washed rock for a nice appearance and future access.

  • Sleeve it like with concrete run boiler systems? (is sleeving a water main allowed? It should be)
    – noybman
    Commented Jul 11, 2019 at 4:10

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