Is 1/2" copper stub out enough to connect to?

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by tokun, Jun 10, 2020.

  1. tokun

    tokun New Member

    Jun 10, 2020
    My main water line is pretty hard to access. I can only get at it through a narrow space between two slabs of concrete. As a result I took off more of the copper stub out than I intended. There is only 1/2" remaining that is accessible. My plan was to connect PEX to it, but this isn't feasible anymore. Is there another way I can connect to the pipe without cutting into the concrete?
  2. Reach4

    Reach4 Well-Known Member

    Sep 25, 2013
    I am not sure what you are describing. Attaching by soldering copper may be your best choice. How about a photo showing the copper you can access, and at least 3 inches around it in each direction.

    If nothing else, dig outside, and bring in a new pipe into the house.
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  4. fitter30

    fitter30 Well-Known Member

    Feb 2, 2020
    Retired service tech
    Peace valley missouri
    Tin the piece of copper coming from the wall. With a clean male pipe adaptor flux everything up feed solder to the inside of the adaptor then use a screwed ball valve . Just remember use a face shield, gloves and long sleeves because concrete will pop when heated. Chisel out around the stub for a better joint with more exposed pipe.
    Jeff H Young likes this.
  5. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    You should install any fitting so that the pipe gets bottomed out in the socket. Now, will it be strong enough and water tight if it's not? Usually, yes, but it's hard to get solder may need to add solder from the other side of the coupler, but that is tougher to get everything done properly and then get the other end soldered, too. If the pipe is in contact with the concrete, that will act like a big heat sink, and it will be really tough to get the pipe up to temp to ensure the solder will flow properly. It would be easy to end up with a cold solder joint. Since you won't be able to really see the other end well, it will be hard to get a good visual inspection of the newly soldered joint.

    A compression fitting also must be bottomed out in the socket, and 1/2" is probably too little sticking out as the compression nut will stick out more until it is tightened, preventing you from getting the valve bottomed, and once you start to tighten it, you may not be able to move it to eventually get it there.

    What I might try is to get a diamond hole saw a bit bigger than the pipe and use it to make a cut around the pipe. You should then be able to probably chip out the cement around it.

    If it really is only 1/2", something like a Sharkbite won't work.

    You may need to repair from outside and stick new stuff through the wall.
  6. Jeff H Young

    Jeff H Young In the Trades

    Feb 27, 2020
    perfect fix fitter 30! a little chipping will insure fitting bottomed out and room to solder.
  7. DIYorBust

    DIYorBust Active Member

    Mar 5, 2019
    Long Island, New York
    How about using an ftg fitting and solder as normal?
    Jeff H Young likes this.
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