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Relocating copper radiant slab floor heating pipe

Hello all, I have a in slab floor radiant heating system. Copper piped inbedded into the concrete. House was built in 1952; no basement. New boiler installed 4 years ago. We currently have a contractor gutting and remodeling a bathroom. years ago one of the bathrooms had a stand up shower; which was at one point turned into a closet. We are turning it back into the shower and having to relocated the drain about 5 or 6 inches in one direction. Long story short we need to cut a small section of the copper piping out and move it over. The contractor wants to basically put a couple 90 degree bends in the pipe to make room for the shower drain.

Is this an OK practice? I don't know how high pressure the water is going through the line but it seems that adding that kink in the link will disrupt the flow of water. The attached picture shows the existing pipe and the orange line represents the proposed bend. Thank you!


Comments

  • Ironman
    Ironman Member Posts: 7,367
    Kinking it is not acceptable; properly bending it is. However, given the age of it, and the fact that concrete has a deleterious effect on copper, I would not recommend bending it.

    They make copper saddles in 1/2" & 3/4" which most supply houses can get over night if they don't have them on the self. That's what I'd recommend.

    It looks like it's already been damaged in a couple of places.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Gordy
  • Jamie Hall
    Jamie Hall Member Posts: 23,170
    If you are talking about 90 degree elbows soldered into that pipe -- four of them all told -- you may be alright. The extra head loss will reduce the flow some, but probably not enough to make much difference. If you are talking about trying to bend the pipe itself, just don't even try. It will either kink (and shut off the flow) if you are lucky, or break -- and not necessarily where it is visibly exposed.

    As Bob ( @Ironman ) said, that pipe looks like the concrete has already attacked it somewhat, so be really really gentle with it.

    Frankly, if it were mine, I'd move the drain...
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • Ironman
    Ironman Member Posts: 7,367
    Why relocate the drain? Are you using a pre-fab shower base? If you use a field-fab one, the drain can be located any where in the base.

    To be honest, I would NOT let a remodeler or everyday plumber touch that radiant system. Get a hydronic/radiant contractor.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    Gordykcopp
  • hot_rod
    hot_rod Member Posts: 22,024
    Clean the concrete from around it, cut the section out and if it is soft type copper use an expander tool to make a fitting on each end.

    Then use copper ells and copper tube or a short piece of pex tube to build a loop around.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,455
    I wouldn't touch it, leave it as is. If you try and splice it you will probably end up going back into it and now the shower will be in the way.
  • Ironman
    Ironman Member Posts: 7,367
    edited June 2017

    I wouldn't touch it, leave it as is. If you try and splice it you will probably end up going back into it and now the shower will be in the way.

    Ed,
    I think that they're gonna have to do something: it looks like the contractor already punctured the pipe.

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • Ironman
    Ironman Member Posts: 7,367
    IDK why the contractor broke up the floor without first determing where the pipes were. An infrared camera with warm water in the tubing, or even an IR thermometer, would have located the tubing.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • BobC
    BobC Member Posts: 5,476
    That pipe is 65 years old - RETIRE IT. Copper pipe in cement was never a good idea, it's only a matter of time before it starts leaking.

    You can replace it all now or you can replace it all later but it is all going to need replacing and it will happen at the worst possible time if you wait.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Gordy
    Gordy Member Posts: 9,546
    @BobC I disagree it depends on the concrete, and soils. I just sold my home which was built in 52 copper was fine in the basement slab, and apartment structure which was slab radiant. Don't throw the baby out with the bath water.

    I'm perplexed. There was a shower, then there wasn't. Now you want one what happens to the old drain?

    If copper tube is damaged splice in soft copper with genial bends around the new drain.

    Mix up a new concrete patch using straight Portland, sand, and aggregate. Fly ash will eat copper.
  • BobC
    BobC Member Posts: 5,476
    I agree it does depend on the mix used and the soil it's all laid on but in the northeast it's usually a matter of when they fail not if.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • hot_rod
    hot_rod Member Posts: 22,024
    If you like the floor heat, take the time to make the repair and adjustment.

    But have a plan B in mind for when the tube does start to fail, no material lasts forever.

    65 years is a good service life for copper in concrete, most would agree.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream