Moving a toilet

[jay surfs]

Hello dudes. I live in Los Angeles County. I demoed my entire 2nd floor. The upstairs bathroom is directly above the first floor bath that is on a cement slab. I have been reading code and trying to come up with a workable new bath layout. My understanding is the toilet drain needs to be 3” pipe and under 6’ in length, or 4” up to 10’ in length, and requires ¼” drop every foot. Correct me if I’m wrong.

I do want to try and stick with code, although not necessarily CA code. I figure if a different code works in another state, then it must be a safe and reliable method, and I’m willing to use it.

I’m guessing the joists would not accommodate 4” pipe in such a long run. But would lowering the lower bathroom ceiling a little make it work?

Is there any way to make this potential layout work? Cutting through all those joists seems like a pain in the ass, especially diagonally. Would it work if I make straight lines with one angle piece? Of course that would make it about 11’ or longer.

Thanks much.

 

[Terry]

I would run 3" below the floor joists and wet vent with a 2" pipe to the lav. Bringing in the lav cuts down the length of the arm.
You can't run 4" through those joists and even 3" would be removing an awful lot of wood there, No more than a 1/3 of the joist, and 2" minimum left on the top and the bottom of the floor joist.