Home>Discussions>PLUMBING>Tying into existing plumbing
3 posts / 0 new
Last post
Zymes
Tying into existing plumbing

I'm planning on adding an upstairs bathroom in my house and I've gotten two different opinions from plumbers I've had look at the job. There is an exisiting cast iron vent pipe which looks to be 4 or 5", (which is also the drain for the downstairs toilet) running through the space where I plan to add the upstairs bathroom. One plumber says I can tie my new bathroom into this pipe for drainage and the other plumber says I must install an entirely new drain pipe with a separate vent. Who's right?

i.m.plummin
Re: Tying into existing plumbing

The second plumber is right you do not stack another bathroom group over a toilet. The new plumbing should tie in downstream of the toilet and its vent. The new plumbing's vent cantie into the existing vent with its offset starting 6 inches above the floodrim of the highest fixture.

Zymes
Re: Tying into existing plumbing

To i.m.plummin from Zymes: Thanks so much for your feedback. I really appreciate it.

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.