Hello all! This is my first post- renovating my first bathroom, need advice. Have done lots of homework, but need experienced advice. Situation: Going from tub/shower insert to standup shower. Drain was on left side, now needs to be centered. This was the tub's drain and overflow. I then opened it some more, and then more. That last picture shows where the drain needs to go- right over the bottom joist and PB pipes, circled in pencil. Obviously, these are both in my way. The joist is sistered, by the way. This is where I'm at. I've notched the sistered joist, and drilled the 2.5" hole for the 1.5" ABS to come through. The 1/4" / foot slope works fine through the joist. The problem is I can't get the P-trap low enough because of the PB pipes. Since it's so high, it won't line up with the pipe coming through the hole in the joist without taking a drop of a few inches. My solution to avoid make a drop right after the P-trap (thus making an S-trap) is to have a waste arm (of 2 times the diameter of the P-trap), then a 90* elbow down and another to meet the pipe through the joist. This is the contraption, and this picture and this picture show how it is mocked up. So. Is this setup crap, or will it work? Will I get siphon effect like an S-trap, or will the two 90* elbows drop cause a problem, will this flow? Thank you for any help you can offer! Dave Ruel
