3/4 inch or 1/2 inch for vertical pipes.

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by ario, Sep 30, 2004.

  1. ario

    ario New Member

    Sep 29, 2004
    I am going to run 3/4 copper for my horizontals and was wondering if there is any advantage to doing 3/4 for the verticals? I want a powerful shower and even though the shower vavle openings look kinda small, I thought maybe 3/4 inch would be better than 1/2 inch for the supplies and head?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    The only time you might need 3/4" is if you have more than one shower head outlet. "Standard" new showerheads are flow restricted, and 1/2" is plenty. Having 3/4" is almost a necessity if you have more than one. It also helps to fill the tub faster, if your valve is designed for 3/4" inputs (some are, most aren't). It depends on how many outlets are open at the same time. If you have many on a 1/2" supply, you may not be able to maintain pressure - then 3/4" (or even larger!) may be necessary.

    Not a pro...
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  4. e-plumber

    e-plumber DIY Senior Member

    Sep 1, 2004
    New York
    Pipe Sizes

    If you're referring to the water supply piping in the bathroom wall and you're installing a regular shower valve with one 2.5 gallon per minute head, 1/2" feed lines for the faucet are adequate, especially if the inlets to the valve are 1/2".
    Now if you are talking about horizontal lines in the basement and asking which size piping to bring up (vertically) to the bathroom, it would be 3/4". I always pipe 3/4" copper feed lines to the second to last fixture.
  5. LonnythePlumber

    LonnythePlumber Plumber, Contractor, Attorney

    Sep 6, 2004
    Plumber, Contractor, Attorney
    Wichita, Kansas

    Much of what is considered power from a shower comes from the quality of the shower head. It's design to incorporate air into the water gives the feeling of force or power. An $80.00 shower head is worth as much as the valve.
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