I'm pouring a new slab over new sewer lines in the basement. I have almost zero depth between the top of the slab and where the drain pipes need to be, because of where we tie into the side sewer.
So the question is: is there a *code* requirement for how deep under the top surface of the slab the drain pipes need to be? Can they be just under the top surface? 1"? 6"? etc.
I may need to use 1/8" per foot instead of 1/4" like I've been assuming.