Help with supply for Grohe Atrio Roman tub filler

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by backwaterdogs, Mar 21, 2010.

  1. backwaterdogs

    backwaterdogs New Member

    Messages:
    51
    Location:
    Illinois
    Hello,

    I'm installing a Grohe Atrio roman tub filler faucet. The supply lines I have are 1/2" (but 3/4" not too far back). The inlet to the valves are and spout are all 3/4" and was wondering if the supply should also be 3/4".

    The rated flow for the faucet 13.2 gpm and it's filling a big darn tub. I don't want to sacrifice flow, so can get 3/4" supply if need be.

    Also and this may answer the above question, but there are two valves, 1 hot 1 cold and you need to plumb from each supply to the valve and the outlet from the valves 'T' into the spout. How would it be best to plumb this? Should I sweat in threaded adapters and use flexible supply hose or sweat copper in between everything? Hose would probably a lot easier for me and not sure if I can safely sweat everything...very close to an acrylic tub! I assumed all the flexible stuff will be 1/2" tho.

    I am leaving an access panel and this won't be getting inspected, so PEX is an option for me too.

    Thanks for all your help!
    Last edited by a moderator: Jun 8, 2011
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
    The flow through 3/4" is nearly double that of 1/2", so run 3/4" to your 3/4" valve. Pex is too restrictive for your application - while the outside is nominal for 3/4", the inside is barely bigger than 1/2" copper since the wall thickness is greater. You don't want any hoses in that connection. I'd solder it. You can buy heat shields to aid you in keeping heat away from parts you don't want to. Keep a spray bottle of water around, too. If you are not comfortable, a plumber might be a cheap alternative to ruining the tub.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,650
    Location:
    Cave Creek, Arizona
    IN many cases, trying to fit hoses into that area will create some very tight bends which could "kink" the hoses and reduce their capacity.
  4. Basement_Lurker

    Basement_Lurker One who lurks

    Messages:
    668
    Location:
    Victoria, BC
    If you have 3/4" trunks nearby, you should take advantage and run them to the tub. I wouldn't mess around with trying to solder inside the access port as you will only destroy the tub, and using braided flex hoses is a bad idea in a concealed space (even though there is an access panel). You are better off saving yourself a lot of grief like these guys are telling you and hire a plumber.
  5. backwaterdogs

    backwaterdogs New Member

    Messages:
    51
    Location:
    Illinois
    Grohe Atrio Roman Tub filler install

    Hey all,

    Am installing a Grohe atrio roman tub faucet and this is different from any faucet i have don as the spout and control valve are all separate.

    Basically, each control value has 3/4" 'T' (sweat fittings). My supply is 1/2.

    Would be very difficult to mount everything and sweat the joints as the tub deck is raised and I'd burn the tub up or something.

    I guess i will need to sweat a threaded fitting and use flex hose.

    Is this a big issue? It's going behind a tile access panel.

    Also, 1/2 supply to this 3/4" faucet..is that ok?

    [​IMG]
    Last edited by a moderator: Jun 8, 2011
  6. Terry

    Terry Administrator Staff Member

    Messages:
    15,011
    Location:
    Bothell, Washington
    You can prefab much of it before it's installed in the deck.
    If you have 1/2", that will be fine. It's better with 3/4".
    Don't use the flex connectors in that location. They reduce down to 3/8", which will increase fill time by quite a bit.
    Also, once the tile goes in, you will have no way to replace them, and frankly, I don't consider the flex connectors are being permanent.

    Normally, I solder on some street 90 els and point them down with sections of copper pipe. That gets me away from the deck, and then say about six inches below I can start to connect them up.

    If this was run in 3/4", you would have 12.6 GPM at 45 psi

    [​IMG]
    Last edited: Jun 8, 2011
  7. backwaterdogs

    backwaterdogs New Member

    Messages:
    51
    Location:
    Illinois
    thanks for the reply, terry!

    I have messing w/ this project for too long...started awhile back and got side tracked...I see where I should have stayed focused...could have gotten to the 3/4 line if i done back when I started...but too late now, basement ceiling is finished now...will have to live w/ 1/2.

    Will follow your advice tho and drop down to avoid the tube...will solder everything.

    thanks again!!
  8. harmonk

    harmonk New Member

    Messages:
    1
    Location:
    Amsterdam
    Hi Terry,
    New to this site, and looking for info about a Grohe bathtub faucet. I am trying to replace washers etc inside it, and can't remember the order of some parts. Where did you get this exploded diagram? It would be a great help for me here.
    Thanks in advance for any info. Cheers, Mk






  9. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,023
    Location:
    New England
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