installin a upstairs bathroom


Old 05-06-13, 06:19 AM
Thread Starter
Join Date: May 2013
Location: usa
Posts: 1
Received 0 Votes on 0 Posts
installin a upstairs bathroom

Im finishing a upstairs in a modular home and i want to put a bathroom directly above a bathroom thats downstairs. there is a 3" pipe that comes from the downstairs bathroom and vents out the roof. I want to connect the bathroom upstairs to that existing 3" pipe. I have a couple plumbers look at it and some say yeah you can no problem then some say you can but i wouldnt and then some say no. what do yall think. I know my code may or may not allow it but want to know the feeling of everyone. thanks
Old 05-06-13, 06:46 AM
Banned. Rule And/Or Policy Violation
Join Date: Apr 2013
Location: USA
Posts: 4,294
Received 0 Votes on 0 Posts
No one here can see what your seeing, need some pictures or at least a drawing.
Old 05-06-13, 06:55 AM
Join Date: Jan 2012
Location: Canada
Posts: 2,743
Received 18 Votes on 16 Posts
Are you planning to add another vent, or tie into the existing vent with a tee (branch going to new bathroom, straight section going straight up to a vent)?

I'm no pro, but this idea I described could cause issues if the two bathrooms are being used at the same time.
Old 05-06-13, 08:14 AM
lawrosa's Avatar
Super Moderator
Join Date: Dec 2010
Location: Galivants Ferry SC USA
Posts: 18,154
Received 68 Votes on 60 Posts
No you cant tie in directly at floor level. You must tie in below all 1st floor bath vents.

Like this. And it means you need to run a seperate 3" line down to the basement or crawl.

Old 05-06-13, 09:06 PM
Forum Topic Moderator
Join Date: Sep 2005
Location: USA
Posts: 5,658
Received 173 Votes on 154 Posts
Mike (Lawrosa) hit it dead on. The 3" vent is being used for the bathroom and probably your whole house vent. Per most (all?) plumbing codes, you can't use that vent for another bathroom.

The layout of course has to be adapted to your bathroom, and only change I'd suggest is that the vent from your new bathroom I believe needs to be 2" (minimum required for a toilet, regardless of DFUs).

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: