basementframingplumbing
Dug out the drain box for my basement shower/tub drain. It's about 2" off from where the tub drain will line up. I need it to b 14 5/8 from the stud wall per the installation instructions for a 30" tub. The pipe in the floor is 17" away from the wall right now.
Can the plumber offset the drain/trap to line up, or would it be better to move the wall closer to the drain?
From your description it doesn't sound like you are actually seeing sewer waste water emitting from the shower drain, but you do smell sewer gas in the shower area. Most likely you have a drain ventilation problem. When the toilet is flushed, the water entering the drain displaces the air that's already in the drain pipe. If the pipe doesn't have sufficient ventilation it will push the stinky air out of the easiest opening (your shower drain).
I believe I found the answer to my own question at this link: when to use a wye or sanitary T. It says " When connecting any vertical waste drop to a horizontal run the proper way to do it is to either use a Wye & 1/8 bend (45 deg), or a Sanitary combo. A sanitary combo is a combination Wye & 1/8 bend already made in one fitting."
I believe this also addresses the concerns I had with the venting.
Best Answer
If the J bend is not in place yet the pipe will need to be cut back to add it. Then with that in place the drain can be lined up to the right spot.
That blocked out portion of concrete is just for that purpose, get the pipe close, then fine tune it when the final hook up happens.