(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 2 of 2

Thread: toilet plumbing from above

  1. #1

    Default toilet plumbing from above

    I'm starting a bath remodel. Second floor hall bath. The location where I want to place the toilet is such that it will be extremely difficult to do the plumbing from below. Is it common to pull up the subfloor to do the plumbing? I'm concerned about positioning of the toilet waste drain, reinstalling the subfloor, and then installing the closet flange. Is this a simple matter? Thanks

  2. #2
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    New England


    You can do it from above...just don't fall through!

    The biggest things are maintain the proper slope, keep the venting working properly, and don't compromise the strucure.

    Depending on whether you have 3 or 4" waste line for the toilet can vary what you do. Trying to maintain slope when moving with 4" can be a big challenge since the bends are deeper than available with marginal joists.

    If the pipe is 4", it's easier since you can use an internal flange - just run the pipe high, install the subflooring, then the finished floor right up to the pipe, then install the flange after cutting the pipe to the proper height. If it is 3", you need to leave a space around the pipe to allow the flange fitting to slide over the outside of the pipe. If you didn't catch this - the proper position of the flange is the TOP of the FINISHED floor, not on the subfloor
    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