Will this layout work utilizing existing vent?

Unwavering · 2025-03-11T10:43:06-0400

Remodeling a half bathroom. Really not looking to have to move the vent and punch a new hole in my roof. The toilet is being moved from just in front of the vent to 5'5" to the right. Total pipe distance between flange and vent would be roughly 10' based on the rough layout above, but I could probably get it down to around 7' with some tweaking if needed. I'm in Florida so under IPC and if my researching is accurate, either way, I'm within the 12' maximum. The shower and sink will be new and have an AAV in the vanity under the sink. Any issues with this layout or anything I need to change? My other option is to run an AAV off the toilet trap. Or do I need to suck it up and punch a new hole in the roof? Any advice is appreciated.

havasu · 2025-03-11T11:47:37-0400

This is not my forte', but I believe you need a vent to your toilet.

Unwavering · 2025-03-11T12:42:22-0400

havasu said:
This is not my forte', but I believe you need a vent to your toilet.

Yeah, I think you're right. Do you think adding an AAV to the toilet line would resolve that? The "void" between the toilet and the door is a utility closet accessible from the adjacent room. I could run an AAV off the toilet trap into that closet so it's easily accessible should issues arise.

havasu · 2025-03-11T13:45:38-0400

Since AAV's are still not permitted in certain states, I'd recommend for one of our experts to chime in, once they finish up the day's work.

MicEd69 · 2025-03-12T00:28:16-0400

Under IPC, your toilet is vented just fine. IPC pretty much says that there needs to be a vent somewhere in your DWV system. UPC is the code that has strict dimension requirements for toilets. But I do assume you have a 3" main vent stack downstream, correct?

However, your shower might have a venting issue. Some jurisdictions do not allow AAV at all, and I'm not sure you can wet vent a 2" shower drain and dry vent a sink with a single 1 1/2" AAV. It would be much better if you would continue the vertical line between the sink and the shower up that wall and connect it to the 2" existing vent line in the attic and eliminate the AAV.