Valve Size For Shower

Discussion in 'Shower & bathtub Forum & Blog' started by gregory d, Jan 6, 2006.

  1. gregory d

    gregory d New Member

    Messages:
    5
    Hello everyone my first post here, came over from John Bridge Tile Forum. Will start with a THANK YOU for this site. I'm in the process of re-doing the shower I have bought the valves they are Grohe 3/4" inlet/outlet. A thermostatic for the temp and two dirverter valves also 3/4" , one for the Hansgrohe "RAIN" hand held shower head and one for the 2 Grohe body sprays also 3/4" inlet. House has galvanized plumbing that will be replaced after bathrooms are done. The hot water heater is just on the other side of the side shower wall, runs under the house with 3/4" then into 1/2" in run the length of the house with 1/2" branches to the sinks and shower (1 shower 2 Kohler toilets) the cold is 3/4" the length of the house with 1/2" branches to the needed areas. After the bathrooms are done the house will be repiped with copper

    * My question is will I have better pressure with the 3/4" valves or should I have bought 1/2" valves I can return them but 15% restock fee. THANKS
  2. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    With 1/2" feeding the shower it won't help to have 3/4. If you can repipe with 3/4 all the way to the shower then yes it will give you more volume. The pressure won't change.
  3. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

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    22,021
    Location:
    New England
    Can you get from the hot waterheater with the 3/4"? You said it was on the otherside of the wall...
  4. gregory d

    gregory d New Member

    Messages:
    5
    Thanks for the quick replys, yes I can get the 3/4 " from the water heater to the shower hook up the cold is already 3/4" so no problem there. The hot will have to be 3/4" to the shower but it will have to hook back into the 1/2" further down the line, it will only be this way for a few months untill I finish both bathrooms then repipe with copper

    *Will it be OK to hook back into the 1/2" further down the line as long as the 3/4" goes to the shower supply
    *When the house gets repiped should I use 3/4" for the hot up to the branch lines then branch off with 1/2" (except the shower)
  5. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    As long it is 3/4 from heater to shower valve you are fine. Tou can go to 1/2 after that or can T off the 3/4 to 1/2 on the way to the valve.
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,647
    Location:
    Cave Creek, Arizona
    valves

    The opening in faucet valves is ALWAYS a lot smaller than the pipe size, so even the 3/4" valves will have ports that are smaller than your 1/2" pipe, therefore you will get more flow from the 3/4" ones than you would from the 1/2" valves.
  7. gregory d

    gregory d New Member

    Messages:
    5
    Thanks again for the replys. I got all the old stuff out of the way and capped off, had to move a gas line also, as I'm adding extra floor joist for support for the tile in the shower. I'll be able to run the 3/4" from hot water heater tomorrow and cap that until I get ready to hook up the valves. I'll go with copper from there into the walls using di-electric unions untill my neighbors plumber will be able to get to my repipe. I'll keep everyone updated and again thanks to all :)
  8. Cass

    Cass Plumber

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    5,980
    Location:
    Ohio
    You should install a new ball valve on the water heater while your at it.
  9. gregory d

    gregory d New Member

    Messages:
    5
    Hey Cass your not kidding I went to check the valve on the water heater incoming and it wont even turn! Its a gate style. The sections of old pipe I took out dont look to bad, but being that the house was built in 1956 its probably just a matter of time before those galvanized pipes give me problems.
  10. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    When you get the ball valve be sure it is full port.
  11. gregory d

    gregory d New Member

    Messages:
    5
    Hey everyone, got another question.

    When I get ready to put in a new main line from the street should I use
    1 in. or is 3/4 in. sufficient ?

    My house has just 2 bathrooms and the normal kitchen sink another in the garage and a couple of hose bibs dishwasher and laundry. Also would the meter need to be changed if the 1 in. is used ?
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