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Lynne
Another vent question

We're planning on adding a below-grade bathroom. Luckily the plumbing is all accessible.

The P-trap for the upstairs bathtub is attached to the top of a 2inch vertical pipe. The end going thru the ceiling (first floor subfloor) is presumably a vent. The other end drops about 18" and is attached to the outflow pipe.

Can we move the P-trap down about a foot or so in order to add vents for the new basement fixtures above it? Is that a bad idea?

Thanks!

dj1
Re: Another vent question

Is there any way you can attach photos?

johnjh2o
Re: Another vent question

You can not connect to the vent in the basement. It must connect above the floor rim of the fixture. That being 42" above the bathroom floor. If you connect to the tub vent in the basement and the tub drain should become plugged the waste water would run down the vent for the basement fixtures.

John

Lynne
Re: Another vent question

Sorry, can't post pics.

I see what you mean about the possibility of a clog in the tub plumbing forcing water up to the basement fixtures vents. Had't thought about that.

Is it OK to run a new vent pipe next to the existing one, provided there's room? It would run through the same wall upstairs that the existing one does.

johnjh2o
Re: Another vent question

That would be the way to do it. You can connect it to the tub vent but it must be 6" above the flood rim of the fixture.

John

Lynne
Re: Another vent question

Just make sure I get this.. the P-trap and vent I'm talking about is for the first floor tub. The bathroom sink vent must be 42" above the top rim of the sink. So I could use the existing vent if I can tie in at about 78" inches from the basement floor?

Sorry to be so dense.

johnjh2o
Re: Another vent question

The vent must tie in 42" above the first floor. By first floor I don't mean the basement floor. If the basement ceiling is 8' then the vent has to tie in at 8'-42" above the basement floor. I don't understand were your getting 78" from.

John

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