I am adding a bathroom in my basement, with the new toilet immediately in front of the existing stack, the sink just next to the toilet (30" CL to CL of main stack), and a shower stall next to the sink (70" from CL to CL of main stack).

My questions are:

- do I need to vent the shower and sink separately from the main stack? I can access another vent on the first floor and run the basement vents up and tie in above the lowest drain on that vent.

- can I "Y" into the toilet drain pipe to the sink and shower with a 2" drain? Or do I need to tie into the main stack separately from the toilet branch?

Just wanted to know to ensure I bust up the floor in the right spots.

Thanks for your help!

I am adding a bathroom in my basement, with the new toilet immediately in front of the existing stack, the sink just next to the toilet (30" CL to CL of main stack), and a shower stall next to the sink (70" from CL to CL of main stack).

My questions are:

- do I need to vent the shower and sink separately from the main stack? I can access another vent on the first floor and run the basement vents up and tie in above the lowest drain on that vent.

- can I "Y" into the toilet drain pipe to the sink and shower with a 2" drain? Or do I need to tie into the main stack separately from the toilet branch?

Just wanted to know to ensure I bust up the floor in the right spots.

Thanks for your help!
Why not connect the shower to the lavatory drain line and let one vent.(see image) cover the entire installation? Sound like a plan? Let me Know, Tom

Looks good, Tom - thanks! So, the shower Y's into the sink, which then T's into the toilet drain (which then goes to the main stack). Then branching from the shower and sink line, I will come up to one vent (the one of the first floor).

I think that works, and validates what I was hoping would work.

Thanks again!
-Greg

Hi Greg...

You said, "which then T's into the toilet drain"...

This is incorrect here. You cannot use a tee fitting, must be a wye, a wye and 45, a wye and street 45 or a wye combination fitting... ;)

Make sure the sink/shower vent and drain is 2" and that the vent continues up to 2" or larger vent (or out the roof 2").

Mark

Thanks, Mark - I was not careful with my wording there. I do understand that I need a wye and not a tee!

Thanks for keeping me straight, and for the advice on the vent and drain.