Alright, here's what I've got. I bought a renovation project and here's a bathroom that was added on the main floor. First, let's take a look at the gore: shower has no trap and drains into a rubber tee laying on its side, the lav has an S trap then goes down through a banded coupling that's falling off, tight 90 to go horizontal, and then drains uphill to where it's directed into the shower, no vents at all. Tying the masterpiece together is the pipe support system that involves a dog leash.




My plan is to rework the pipes as shown and vent the whole bathroom through an AAV at the lav. The AAV would sit on the opposite side of the wall in the adjacent room behind a cabinet and the trap arm would poke through the wall (cannot go inside the wall because there are joists directly under it). In theory I could hire a plumber and vent it up to the roof later when I have the time and money and have more walls open, if it's even possible, but hoping this flies for now. It's hard to tell from the picture but the horizontal section between the lav drain and the wye for the shower will be flat, and then it will drop down into the branch drain.



Does this plan look ok? Is it ok to wet vent a bathroom group through an AAV?



Edited 2 times.

actually, not too bad.
it is a 1000% improvement
i would turn the 2 inch 'Y' around and run the shower into the end of it and use the side for the lav.
put a cleanout in the lav drain as well.

The dog leash is attached to an EMT conduit LOL.

The elbow below the lav drain rubber connection is a pressure fitting not a drain fitting.

Great, thanks. Will do.



Edited 1 times.

It looks great.



Edited 1 times.