First Floor Bathroom

[RobBeau]

Hello,

Great forum! I've been browsing and searching to try and find information. But I'm stuck on my drain layout. I have a first floor powder room (toilet and sink) and I'd like to add a shower. Due to floor joist layout, and trying to re-use existing piping, I'd like to have the layout shown in the image. But I think there are problems.

1. I think the vertical 3x3x2x2 wye prevents the toilet and shower being wet vented, so I would have to dry vent each of these separately?
2. But if I put the 3x3x2x2 wye horizontal instead of vertical would that wet vent the toilet and shower?

Thanks,

 

[RobBeau]

No one replied, so I got a local plumber to do the work. For anyone else's future reference if they stumble on this post, my plumber told me:

1. A vertical wye doesn't allow the system to be wet vented.
2. A horizontal wye would allow the system to be wet vented, if the 2" runs were less then 8ft.
3. My shower run as shown was longer than 8ft, so it would have need it's own dry vent.
4. My plumber routed the shower drain into the lav, which he said meant it was wet vented and didn't need it's own dry vent.