Bathroom drain and venting help

[ayop]

Hello all, I was hoping I could get some help nailing down my bathroom plumbing:

After demo, I see that the shower was essentially an s trap for drainage: It had the p trap connected directly to the shower as expected however the trap arm had a 90 down to the horizontal drain (it actually had another unexpected loop trying to incorporate a sink drain across the room ... It was a source of a leeek ...

The tub seemed, ok the trap arm was Tee-ing straight to a vent.

My problem now fir the remodel, is the vents seem to be pretty far away and behind my fixtures drain flow, and trying to avoid going through joists and studs is difficult.

After few days of research I have come up with the attached layout that I was hoping to get some feed back on.

My first though for the tub was to use an AAV, it would end up in a dry walled area of the bathroom, but I see it is frowned upon in Canada.

I am hoping the offset traps will be ok, the total developed length is pushing 30" i can always try and tighten it up to get under 24.

As mentioned before the shower was trying to share a drain from across the room in a U' config so i separated them.
In the attached pic, you will see a horizontal 'vent' on the right, it is also the drain for the sink and is actually almost 11' ...

The blue pipes are 2" and orange 1.5"
Thanks again fir any feed back
Kind regards

 

[John Gayewski]

Your tub is trapped twice. You need to pipe around the trap for the shower and not tie into the shower's tailpiece.

An overhead view of the fixture layout might help.

 

[Sponsor]

 

[ayop]

Your tub is trapped twice. You need to pipe around the trap for the shower and not tie into the shower's tailpiece.

An overhead view of the fixture layout might help.

*Edit, I think i see what you are saying now, instead of the tub connecting to the back of the shower, it is better to go around connect on the side? That should be do-able.

Attached is an over head sketch of the fixture layout.

Edit2: added a second image of an alternate route for the shower, where the trap is connected directly to the shower and then somewhere along the trap arm tee-off for the horizontal, then elbow down to the drain line (only elbowing down to avoid going through joist). This would be the best option for me but wasn't sure if venting the trap arm from the side is ok, but it is attached to a sink so i thought it would be...

Thanks for the reply John, best regards