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!

Quote:

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Originally Posted by gdhayden

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!

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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.