adding a basement bathroom to a 3 story house

[bfd8656]

I have a 1951 three level home. I am trying to add a bathroom to the basement directly below the main level bath. I have a 4in stack that I would like to have my new toilet, sink, shower and washer dump into. I would vent all of these fixtures into a 2in vent pipe and then bring that pipe above the highest drain from the main floor fixtures. Will this work?

Eventually I want to add a bathroom on the 3rd floor directly above the current bathroom. Currently the main floor fixtures all drain into the stack and then use the upper part of the stack as their vent. Would I have to do something to the main floor in order to have the 3rd floor bathroom drain into the stack above the main floor bathroom fixtures? I plan on venting the future 3rd floor bathroom fixtures directly through the roof or into the main stack just before the roof.

I have pictures I drew in PDF from

http://www.yourfilehost.com/media.ph...umbing_now.pdf
http://www.yourfilehost.com/media.ph...g_proposed.pdf
http://www.yourfilehost.com/media.ph...r_bathroom.pdf
http://www.yourfilehost.com/media.ph...ld_and_New.pdf

[FloridaOrange]

For the basement bath that sounds fine, the vents would tie into the vent system over 42" above the second floor. If you add fixtures above that stack to the third floor you would have to bring your vents above the third floor fixtures. I would look at the PDF's but after the last fight with a virus I won't download anything. You can post PDF's here (given file size restrictions).

[bfd8656]

They aren't downloads, just hosted on file host, but i understand. They are just hand drawn sketches. The only problem I can see is the existing fixtures don't have "vents" they just dump into the stack. The tub is just below the toilet and the sink is just above. My only worry is that while the basement and the 3rd floor will all have vents that tack into the main stack above everything, my current plumbing will be draining and venting in the middle of a run.

[Terry]

Any waste from above has to tie in lower then the waste below.
Nothing from an upper floor can enter into a lower floor above a vented connection.

If you want to add a third floor bathroom, you can wye or tee in below fixtures. So if you have a 3" or 4" toilet line, you can cut into the wall below the toilet, and wye in a second line. The connection would be below the toilet.

The vent from the downstairs could tie in at 42" to the existing vents on the second floor. Those don't need to extend separately all the way through the roof, but then depending on your walls and circumstance, you may have to anyway.

[bfd8656]

I was under the impression that you could use the main stack for drain and venting if done properly. Is that what "Wet Venting" means? If I'm understanding you correctly. Each of the three bathrooms I would like to have (1 on each floor) would have to have it's own drain stack down into the floor and then they could all connect into the main stack I have now as a vent. Currently the exsisting plumbing has no "vent" going up above where the drain is. I am assuming this is something I am going to have to change.

[jimbo]

. Is that what "Wet Venting" means? where the drain is.going .

No. Wet venting only takes place in a single bathroom group on one floor. No waste can drain into a line which vents a fixture on a lower floor.

[hj]

Your question was answered elsewhere, but to reiterate, you need a new VENT for the basement fixtures and a new DRAIN for the upper level. And the new vent and drain have to be properly installed.