Changing copper to PEX

Discussion in 'Showers and Tubs' started by HalM, Sep 17, 2019.

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  1. Sep 17, 2019 #1

    HalM

    HalM

    HalM

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    Hi,

    Shortly I will be doing a tub/shower replacement in our upstairs bathroom. I have to re-plumb the tub and shower and will be adding a new mixing valve and diverter for a hose/wand sprayer as well. I would like to change the existing bit of plumbing from 1/2 inch copper to PEX. But, I notice that the inside diameter size of the 1/2 inch pex is smaller than that 1/2 copper. Is this anything to be concerned about when doing renos and changing pumbing pipe? Will any pressure be lost? For lines feeding fixtures in a bathroom is there any advantage to change it to a 3/4 inch PEX?

    Thanks,
    Hal
     
  2. Sep 17, 2019 #2

    Diehard

    Diehard

    Diehard

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    If you're not already suffering with a pressure problem it shouldn't make a noticeable difference.
    The reason I say that is....
    1. The low flow rate of a shower at say 2.5 gpm
    2. The amount of piping to be replaced is likely 10 feet or so.
    For these assumptions, difference in pressure loss would only be about 1/2 psi or so.

    If it's a case where you have greater lengths of PEX and cannot stand to lose 5 to 10 psi or more, then you would want to look more closely into it.

    Don't know why they didn't make 5/8" PEX so as to more closely match the flow characteristics of the 1/2" copper. Well I guess it was to stick with the same O.D.
     
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  3. Sep 20, 2019 #3

    Diehard

    Diehard

    Diehard

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    Don't know if you have come across it anywhere but there's been some problems with new mixing valve and diverters when using PEX for the tube spout. Believe it's recommended to stick with 1/2" copper for that.

    Check into it.
     
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  4. Sep 21, 2019 #4

    HalM

    HalM

    HalM

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    Thank you for the info.
     
  5. Sep 21, 2019 #5

    HalM

    HalM

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    Thank you for the info.
    Yes, I've seen some of the issue regarding the tub spout. Advised to use copper to the tub spout.
    Hal
     

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