mixing tanks and bowls?

Discussion in 'Toilet Forum discussions' started by pawclaws, Nov 22, 2008.

  1. pawclaws

    pawclaws New Member

    Messages:
    2
    We're remodelling a powder room and the toilet that was there was hitting the wall. The rough in is only 11", so I'm assuming it was a standard 12" toilet. (All the others in the house are standard, no problems.)

    Unfortunately there are no 10" rough in toilets that match what we want. We're looking for something "old", like the Kohler memoirs or some of the American standard stuff.

    What happens if I try to put a different tank on a 10" rough in toilet. Is there anyway to determine compatibility? Has anyone tried this when replacing a tank?

    Thanks
  2. Terry

    Terry Administrator Staff Member

    Messages:
    14,939
    Location:
    Bothell, Washington
    Most toilets have spec sheets that tell how much space is behind the tank.
    On a 12" rough, that may be as much as 1-1/8" or as little as 1/8"

    Some models have slim tanks ( 10" ) that allow for less space.
  3. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Almost all brands today....the rough in spec is set by the TANK not by the bowl.

    Many common toilets are available in 10" rough, although the selection is limited somewhat. Toilets are a SET. You MUST get a tank and bowl which are designed to go together.
  4. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,534
    Location:
    Cave Creek, Arizona
    tank

    As long as the new tank matches certain key dimensions, it will work. The bolt center to center dimension has to be EXACTLY the same, not just close, and the center of the flush valve to the front has to be equal or less than the original one or the seat may not stay up. IF the center of the flush valve is greater than the original one, then it may require more than a 10" rough.
  5. pawclaws

    pawclaws New Member

    Messages:
    2
    Tank

    So the slimmer tank is what makes it a 10" vs 12" rough?! That makes sense. Looks like I'm stuck with what is available.

    I measured again and i doubt i could take advantage of a 12" that had a lot of space behind the tank. looks like its just under 11 inches. Even with a 1 1/8" spec behind the tank, I think it would still touch.

    Great service. Thanks.

  6. Terry

    Terry Administrator Staff Member

    Messages:
    14,939
    Location:
    Bothell, Washington
    [​IMG]
    This one can be made to work with 9-1/4"
    It uses a 10" Unifit adapter to move the bowl.
    Toto makes about seven models that work this way. ​
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