My home is in Northern Colorado, built in 1997, bi-level with an unfinished "basement" that is entirely above grade, with a rough-in bathroom and a small open space that I want to turn into an office area. With the bathroom area in particular, I'm fairly certain that I've got to move the toilet drain, but I'm also wondering if there's something I'm missing here, because it feels like the house shouldn't have passed inspection at the time it was built.

I'll post the diagram and a picture here, but you can see a full gallery of pictures & captions of my bathroom here on imgur for a little more context or a larger view of the situation.

Diagram of Bathroom Area Picture of Rough In Toilet Drain and Waste Stacks

You can see in the pictures and in the diagram that the edge of the toilet drain is 14 3/4" from the edge of the concrete footing, and the waste stack is in between the two. Even before framing a bulkhead around the waste stacks to conceal them, there's only about 10 1/2" between the edge of the toilet drain and the edge of the waste stack, and the protrusion from the access into that waste stack reduces that down to around 9", before any framing.

I've looked into the possibility of using an offset toilet flange, but that only buys me around 1.5" - 2" at most. As near as I can tell, my only real option here is just to tear up the floor and then move the toilet drain, right? I feel like this is so obviously an issue that the plumbing simply shouldn't have been deemed acceptable when this was first installed 25 years ago, which makes me wonder if I'm not missing some sort of alternative here.

Assuming that this is the case, my tentative plan is to have the drain moved to about 20" off the edge of that concrete footer, and with new framing around the waste stacks, it would be about 12" off the new bulkhead hiding those stacks. That would leave about 44" from the drain to the wall in front of it. I also figure that I'd want to put an access cover in the wall behind the toilet to allow access to those stacks, though I'm not sure if that's allowed to be done behind a toilet or if it would need to be moved up the wall to be more accessible. Appreciate any feedback or wisdom that anyone has to offer!

  • 1
    Waste less space on the plumbing chase (it does not need to be built like a structural wall) and look for a toilet with a smaller "pipe-to-back-of-tank" (rough-in) measurement. 10" is commonly available, and some 10" are nearly 9 in reality. And that's measured from the center of the pipe, not the edge.
    – Ecnerwal
    Aug 4 at 1:38

1 Answer 1


The projecting cleanout plugs can be replaced with inset cleanout plugs, similar to this (there are multiple styles, of similar function) - all of them replace the projecting square part to apply a wrench to with some sort of recess in a flush cover that a tool can be applied to to open and close the cleanout plug.

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Image from https://s3.amazonaws.com/s3.supplyhouse.com/images/products/large/878-30-3.jpg no endorsement implied.

A pipe chase has no structural function, and does not need to be overbuilt as if it did. You want to conceal the pipes, but that's all you need to do - you don't need to build a studwall around them.

You can get toilets with rough-ins of 10" and some nominally 10" toilets are close to 9" in reality. The rough-in is measured from the center of the pipe, not the edge of it. You can also turn the toilet 90 degrees so the pipes are beside the back, not behind it.

It may be worth seeing if your LAHJ has plans on file showing how this bathroom was to be laid out.

  • Reducing the protrusion from the cleanouts by using inset plugs is a good idea, thank you for that. For non-structural framing around the waste stacks, I assume that some standard 2" x 2" lumber would be adequate, right? That would put the bulkhead around 6" - 6.25" off the concrete footer, which should give me just over 10" of clearance to the center of the toilet drain. Plans for the house is another interesting idea that I'll have to run down.
    – WJTownsend
    Aug 4 at 4:47
  • 1
    Put the face of the framing (if you use framing at all - trim boards on each side would be plenty, and waste less of your interior space) in line with the outmost edge of the pipes, and your projection beyond the pipes becomes the thickness of the surface you put across them (i.e. 1/4"-1/2" for typical drywall or cementboard or plywood.)
    – Ecnerwal
    Aug 4 at 11:20

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