The toilet in one of my bathrooms is too close to the shower. I have room and would like to move it about 2 feet. It is also a 14" rough-in and it's hard to find toilets in that size, that are not ~$500 (Toto). I'd like to make it a standard 12" rough-in. The challenge I see is the bathoom is on concrete slab. So, what's involved in moving the toilet drain about 2" closer to wall and 2 feet over? I'm not sure if the drain is plastic or iron but I imagine that would have an impact on the effort.

  • Is it a concrete slab with no cellar or concrete slab that was poured over the sub floor to set tile.
    – mikes
    Commented Apr 7, 2012 at 16:47
  • There is earth underneath the slab. Not sure how thick it is
    – Andrew
    Commented Apr 9, 2012 at 13:30
  • update: I had a plumber jackhammer up the floor and more the drain. They discovered a y-trap? which added all sorts of complication and some cost. It was cast iron but they converted it to pvc.
    – Andrew
    Commented Dec 10, 2012 at 3:33
  • There are offset flanges that will move it the 2", the 2 foot lateral move needs some DIGGING.
    – HerrBag
    Commented Jun 8, 2013 at 21:07
  • I'd cut it with a saw, jackhammer it out, rework the pipe, drill 3/8 inch holes on the cuts, insert rebar & tie it together. But I'm just a plumber so you'd need to get a concrete guy to patch it. Good luck.
    – user48693
    Commented Feb 3, 2016 at 3:32

4 Answers 4


If its on a solid slab you're looking at a jackhammer and some new fittings. If your fittings are cast iron you'll need to be especially careful because its brittle and any concrete removing action around it could cause it to crack. Once exposed you'll be able to see your options depending on which direction the down elbow runs.

  • One guy I talked to suggested cutting through the slab with a angle grinder, then chipping out the concrete in chunks. Does this seem like a workable approach? I"m asking since I wasn't very confident in this guy's abilities/knowledge.
    – Andrew
    Commented Apr 8, 2012 at 14:50
  • 1
    An angle grinder isn't going to have the proper blade nor enough chutzpah to do the job. If you want to try this approach, you'll need a concrete saw. Understand that a saw is usually for precision cuts where you know EXACTLY where you need to cut, for instance to add a window to a pre-existing brick or concrete wall. This is not the case here; you're fact-finding, figuring out where the drain goes and making arrangements to move it. Once you're done you'll patch over what you broke up (which generally works best with a rough edge anyway).
    – KeithS
    Commented Apr 9, 2012 at 16:54

How about a less drastic first step: hire a plumber with a snake scope (or rent the scope yourself from an equipment place). These scopes come with locators, allowing you to trace the path of the plumbing with the locator, and by following the direction of curves on the video monitor. This will show you which way the drain flows and where it connects to a parent stack, allowing you to plan for the move before you jackhammer the slab open. It also makes sure that the existing drain ties into a sanitary line, and not the storm sewer (they're for very different purposes; the sanitary line is for wastewater from within the home, while the storm sewer is for your weeping tile, sump and rain gutters.

A jackhammer really is the tool for the job. An angle grinder was designed to cut/shape metal and was not designed to cut into concrete; it has neither the proper blade diameter nor the proper motor power. A jackhammer is also faster for "rough" cutting like you're going to want anyway. A concrete/rock saw is for precision work like cutting a nice square opening in a brick wall for a new window/door. Once you've moved the plumbing where you want it, you'll be filling in the part of the slab you cut out anyway, and new concrete bonds best to old concrete when the old concrete has rough edges; smooth cuts could cause the patch to lift out of the cut as it doesn't have as much to "grab".

  • Interesting idea on using a scope. While this is a DIY site, I mostly hire contractors to do the work. This site is great because it helps me become more educated and hire the right people.
    – Andrew
    Commented Apr 11, 2012 at 3:56


I moved my shower drain that is located in a concrete floor. Much of the work should be the similar for moving a toilet, just on a bigger scale.

I used an air chisel to chip out the concrete around the drain. I needed to move the drain about 2 inches and the hole I chipped out ended up over 1 foot across. The concrete was only a few inches thick. There was dirt below the concrete (typical for a Phoenix slab home). The chipping went pretty well, just a lot of noise and dust. Wear gloves, eye, ear, and dust protection.

My drain was ABS. I cut off the old pipe and glued on new pipe. Then I refilled the hole with packed dirt and new concrete.

It is a project that seems like it would be a lot more work, but most of the work is just chipping and removing the debris and dirt. I cannot comment on what to do if you have cast iron drains as I have no experience with cast iron.

The digging needs to be done anyway, even if you need to call in a plumber to actual move the pipe.

Keep in mind that once your remove the toilet, sewer gasses can come up through the open pipe. If you shove something down the pipe to block the gasses, make sure it does not go down the pipe. Also try to keep debris out of your drain. You don't want to clog it up.

  • That's great you have ABS. Based on the age of my house ~37 years, I'm told it will most certainly be iron. Apparently ABS was allowed in walls at that time but not in foundations
    – Andrew
    Commented Apr 11, 2012 at 3:58

You can use diamond tools to cut your way through the concrete. Look for "Diamond Coring and Sawing" tools. A good rotary hammer (around 10 Joule or more) will do the job too, but is not so precise and you will damage a larger area of concrete than necessary.

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