(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 3 of 3

Thread: 12" toilet on a 14" rough in on concrete slab

  1. #1

    Question 12" toilet on a 14" rough in on concrete slab

    I have an extremely small bathroom with a 14” rough in on a concrete slab. The toilet that’s in there now I suspect is over 30 years old. It sits 2” from the back wall (wasted 2”) and there’s barely 15” from the front of the toilet to the opposite wall. Very small bathroom.

    1. Need to find a way to install a 12” toilet on this 14” rough in to reclaim the 2” in back of the toilet that’s currently wasted space, without breaking up the concrete on this floor.

    2. Need to find the smallest toilet (lengthwise) available to get as much space from the front of the toilet to the opposite wall. (smallest seems to be the Kohler Realto which is 25½” in length)

    I’ve heard about a rough in adaptor which can adapt a 12” toilet to a 14” rough in. Do you know where I can find it and can it be used with any standard toilet?


    How I can adapt this 12” Kohler Realto toilet to the 14” rough in so it'll sit closer to the back wall (reclaiming that wasted 2") and also allow much needed space in front of it?

    Thanks for any help.


  2. #2
    I&C Engineer (mostly WWTP) Lakee911's Avatar
    Join Date
    Aug 2005
    Columbus, OH


    How about an offset flange? may need to bust up very little concrete to accomidate it.


  3. #3
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    New England


    First, you need to verify the rough-in...measure from the bolts holding the toilet to the flange to the finished wall behind it. If this is indeed 14", then you need a 14" rough-in toilet. When installed, it would normally have about 1/2" or less behind the toilet to the wall. Sounds like you may have a 12" rough-in toilet on a flange set 14" from the wall, thus the large clearance behind it. Most 14" rough-in toilets are no longer than a 12" one, it is just that the trap and bolt holes are relocated (although some are longer). Toto's that are skirted use their Uni-fit adapter. It lets the same toilet work with the standard 12", or by changing the adapter, to either a 10" or 14" rough-in flange location.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014


Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts