Hi all!
We ripped out the tub and are installing a shower upstairs.. I HOPE! The city says I need 2" drainage. I have 1 1/2" in the whole house except for the toilet line...soooo . The inspector says I need to replace the 1 1/2 with 2. ok. so to do that I would either have to gut a wall in my kitchen downstairs and try to find a way to connect to a 3" line somewhere in the cement floor... or ... connect the shower drain to the toilet line which is about 5 ft away.... I think I have it figured. But Im not sure. I dont want to connect things and have a toilet that flushes and backs up in the shower!! yikes! the top of the pipe from the shower is about 1 1/2" below the sub floor. the top of the toilet line is 5 inches below it. in the picture the shower drain will be on the right hand side . I will have to run the pipe through holes cut in the floor joists. In the picture you can see the existing shower drain going to the outer wall of the bathroom. It vents from this spot as well. I believe I would have to use this vent for the shower. ... Does this make any sense?
Thanks in advance for any help!!!!!
Ben

 

From what I can see in the image, it looks like it would be very difficult to use the toilet piping. You would not be allowed to put a wye in the closet bend, and even if you did, you'd be drilling all the joists to get to the shower area (if I'm interpreting it correctly).

The only alternative I can see to replacing the 1½ drain is to find a small corner tub, which would mostly be used as a shower anyway. It might make for a nice shower pan.

 

I've seen it but the joining of the two was beyond the initial turn of the toilet drain line. Also have to consider the number of turns in your new 2" pipe. Too many will render it out of code as there will be too many potential places for clogs to happen. Straighter the better.

 

Not to mention that drilling through all those joists will weaken them. Holes are not permitted at all in the middle 1/3 of the joist span.

Going down looks like the only shower option to me. I can't believe they are making you upgrade the ENTIRE shower drain line to 2". The preexisting should be grandfathered in as long as you aren't moving it. 2" is current code, yes.

 

x -- it was a bathtub and he's converting it to a shower. Lower flood-level requires a bigger drain.