Venting basement bath

benleef

Hi all. I am getting ready to demo my existing basement bathroom for a remodel.

The 3/4 bathroom is currently vented through the rim joist and out the side of the house. I would like to get this properly vented when I remodel. I know as a last resort I can use an AAV, but I would like to do the best job possible if I can manage. I'm hoping I am able to run a new vent alongside the old house stack. I would run it all the way to the attic and either tie to the existing stack or just run this vent through the roof as well (any opinions on which is best/easiest would be appreciated)

Here is the issue--The main vent stack is approx. 15-20 feet from where the vent would rise above the fixture--so I would have to run it horizontally for that length and then up through 2 floors and to the attic. Is this OK? I think I am pushing it space-wise running the required 2" vent as it is (along with couplings), so it would probably be too difficult to upsize it to 3".

Also, any tips on how to run this vent between floors without opening up walls? I can remove my 2nd floor recessed bathroom mirror and I possibly gain access to the area of the main vent stack and possibly fit a short length in there and an even shorter length from the attic and couple them together in the wall and repeat until it gets long enough to reach the basement..will this even work? How can I support the pipe?

Hope someone can give me some advise and/or pointers. Thanks!

Ishmael

The 2" vent is fine, but I don't see how you'll get it through two floors without cutting a wall open somewhere to drill holes. I've had luck through one floor in a one story house - careful measurements to drill up through the lower plate of a partition from the basement, then down through the top plate from the attic. But when you have a 2nd floor to get through, you'll have to cut a hole down near the floor somewhere to drill through the bottom plate of the 2nd floor partition and sub-floor.

That being the case, the vent from the basement can tie into any equally sized (or larger) vent stack on the first floor a minimum of 6" above the flood level rim of the highest fixture on that floor. Another way around it is to run the vent in a corner of a closet, or - just like the old days - right in the corner of the rooms, then box it in with some trim and paint it if that's acceptable to you. But patching drywall is no big deal, either.

benleef

I agree---drywall isn't difficult to cut and patch, but plaster and lathe is...

I did some investigation last night....

I removed the recessed mirror in the second floor bath. I think I can use a bunch of extensions and from the hole in the wall drill through the top plate of the first floor and then drill up from the basement.

However, the stud bay I have access to vertically, lines up with the floor joists horizontally which line up with a window in the basement bathroom. Therefore, if I ran the vent up from the fixtures in the bathroom, in order to get it into the proper floor joists--it would have run up in front of the window. I know this may sound confusing, I'll try to take some pictures....