I need to move the toilet back about 3" from where it was originally set to get to the standard 12" rough-in distance. I had to cut the concrete slab and dig into the dirt below. I was planning on going down to just above where the pipe enters the main drain line and adding in two 22.5 or 45 degree connectors to displace the top of the pipe to the proper location, but to my dismay there are 2 copper pipes running in the way about 2" below the bottom of the slab so I won't be able to move the toilet pipe, but will need to use an offset flange.

The offset flanges I have found only have about a 1.5" offset. Can I stack 2 of these, to get the offset I need and go over the pipe, or is going over the water pipes or stacking 2 offset flanges a code violation? At this point I'm into this pretty heavy so almost any solution is possible EXCEPT trying to move the water pipes. Any input is welcome.

Additional Info:

The distance from the top of the copper pipe to the top of the new tile floor will be 7" at the back of the pipe to 7.5" at the left. The wall is to the left and the 2 black dashes on the top/bottom are the 12" marks.

Hole in slab

  • Yep, you're right, No P-trap. I corrected it to the main line. Also, my daughter doesn't want me to cut into the water lines. She's afraid of possible problems if I don't do a good solder job, and I don't trust Shark-bite below ground or on old possibly out of round pipes.. I'll try to get a photo tonight if I can. Jan 9, 2019 at 20:12
  • Which direction does the drain exit the scene?
    – isherwood
    Jan 16, 2019 at 17:22
  • Is that a raw pipe stub we're seeing? Sure seems like there's room for two 45 elbows below a flange. No?
    – isherwood
    Jan 16, 2019 at 17:25

2 Answers 2


I hate to say it, but there's really no alternative to excavating this and rerouting the drain line. The reason offset flanges are so limited is that they are MUCH more prone to clogging. I've heard they're not even allowed by code in some areas for that reason.

I don't trust Shark-bite below ground or on old possibly out of round pipes

Shark-bites are fine below grade. If your copper pipes are really so bad off that you can't shark-bite them, you've got larger issues.


It may not be code compliment but you could try transitioning to PVC with a ABS PVC bushing and heat bending the PVC and transitioning back to ABS to finish off with the toilet flange. Sound crazy but it works.

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