It's been a long time since I posted about this stupid rough in (dang kids), but I'm attempting to get back on it. The spacing for these pipes are driving me crazy.

enter image description here

For a quick reference, the following pipes are as follows

  1. Drain and vent for basement sink
  2. Toilet rough-in
  3. Backwater Valve
  4. Tub Drain

The idea to finish the bathroom as such: enter image description here

There are 3 big problems (for me) with this rough in.

  • 2 is 15.5" on center from the foundation wall. If I were to leave up the current insulation and put up a wall, I'll run out of room. The current insulation can poof anywhere from 3-4". If I were to put up a 2x4 wall with 0.5" drywall/cementboard, I'm looking at loosing 8" of that 15.5". That means the toilet hole is only 7.5" from the finished wall. That's not gonna work. If I were to rip out all of that perfectly good insulation and put up 1.5" XPS, that still only leaves me with 10", which is no where near the standard 12.5" offset from wall. How can I possibly frame that wall so that it A) still has insulation (in my state we're required to have R10/13 in the basement) B) is wide enough to enclose the #1 pipe (which is slightly more than 3" from the foundation all to the outside of the pipe) and C) leaves enough room to place a toilet without an offset flange.

  • 2 is 49.5" OC from the wall on the right. We'd like to place a stand up shower where #4 is. But doing the math, if code requires a MINIMUM of 15" OC for a tub to the shower wall and 30" MINIMUM for the shower INTERIOR space, that only leaves me 4.5" to put in insulation, framing, cementboard, AND THE FRAME FOR THE SHOWER. Since there are no wires/pipes to run on that wall, I could get away with 2x3" furring strips? To get an R value of 10, I'd need 2" of XPS, plus the 1.5" of the furring strip + 0.5" cement board. That only leaves me 0.5" to do the exterior of the shower. If I'm doing a tiled shower with a step in, isn't that going to be at least a 2x4 and then some?

  • 3 and #4 are so close to each other. There's roughly 8-9" between the two for me to fit the wall with the pipes. There's no way that I'd be able to put in a tradition square center-drain shower in there. Will I have enough room to put in the wall and be able to have a free standing shower?

1 Answer 1


Given multiple issues there, I think the correct and possibly simplest, albeit messy, solutiion is going to be cutting the floor open and putting the pipes where you need them.

Concrete is not forever.

  • I'm just confused as to how this is even possible. I can maybe see how they get away with the shower because they normally put in a tub shower and those have smaller clearances, but I can't fathom how the toilet would work. And it's infuriating because we paid to have them put the rough-in in. Jul 20, 2014 at 13:32
  • You might ask "them" what they were thinking, and/or point out your issues with it and ask "them" to remedy it. They might say "Oh my, we screwed up, we'll be happy to fix that for you" and they might not. The big question is who specified where things were to go? You, your architect, left up to the plumbers...? That's where the blame lies. If you had specific fixture and layout and wall insulation methods in mind, and failed to communicate that information to the plumbers, they are not really at fault here.
    – Ecnerwal
    Jul 20, 2014 at 13:41

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