[Queso Bandit]

I'm fairly clueless so I'm hoping for some advice...

I'm doing a bathroom remodel in a home with a crawlspace and relocating the w.c. The sink has it's own vent and the new w.c. will be installed about 3 ft down-flow from the sink. A shower drain will connect between the w.c. and lav. but the shower has it's own vent.

Do you think it's necessary to install a branch vent up from the w.c. and into the sink vent? I'm hoping not.

Also, is there any reason to tie into the old cast iron stack about 18" from the ABS lav. vent? I was thinking of abandoning it and adding a clean-out at the end of the main line.

If there is enough slope to work with, would it be better to tie the shower drain into the 2" lav. drain (instead of the 3" main)?

hmmmm.... i drew a sketch.
thanks in advance.

 

[JDC]

If the governing code in your area allows wet venting then you're close....

If you lay the 3X2 wye to the shower on its side so its coming off at the same horizontal plane as your main then it doesnt need a vent. The lav vent will serve as a wet vent for the entire bathroom group. If your water closet is directly above your main then you're fine. If you need to run over some to catch it, turn the wye on its side too then 90 up to it. (hope that makes sense, but it sound kind of confusing now that I read it). The end of run clean out is not a bad idea at all.

You can tie your vent into any existing vent that eventually goes through the roof whether it be cast iron or ABS.

Again, hope this makes sense. Writing this at 7am after a long night of "fun" lol

 

[Queso Bandit]

Thanks JDC!
So the wye for the shower should be attached at the same plane as the main? not about 45 degrees upwards?
the shower has it's own branch vent.

Same question with the w.c
If I can't squeeze it in directly above the main, should it enter the main on the same plane? or try to maximize the angle of entry off the main drain?

 

[JDC]

If the shower has its own vent then it can angle upwards. If you want to eliminate the shower vent then it needs to come off on the same horizontal plane as the main. The same goes for the toilet. However, if space is limited and you cant do this with the toilet then you should be fine with how you have it drawn. Its not "quite" perfect, but it should work just fine.