Will this layout work utilizing existing vent?

[Unwavering]

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]

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

 

[Unwavering]

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]

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]

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.

 

[Twowaxhack]

Change all the wet vent to 2”.

 

[Unwavering]

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.

I appreciate the reply and info. I had considered running a vent up through that wall, but the existing vent is on the exterior wall with a low pitched roof. there's only about 5" of clearance between the top plate and the roof. Not sure I'd have the clearance to connect there. That's ultimately why I settled on the AAV. The AAV I'm looking at is rated for up to 24 DFU's on a stack so I thought it would be okay. This is it.

I'll see if I can get in there today to determine if running a dry vent through that wall and connecting the to existing will work. Thanks again.

 

[MicEd69]

A lot of people, including me, hate AAVs. A vent to the atmosphere is MUCH better.

The wet vent portion of the shower vent needs to be 2" as Twowaxhack said. That means the tee you use for an AAV should be a 2' x 1 1/2" x 1 1/2" tee like below on its back. If you can get an atmospheric vent in, this same tee should be used as it is pictured.

 

[Unwavering]

A lot of people, including me, hate AAVs. A vent to the atmosphere is MUCH better.

The wet vent portion of the shower vent needs to be 2" as Twowaxhack said. That means the tee you use for an AAV should be a 2' x 1 1/2" x 1 1/2" tee like below on its back. If you can get an atmospheric vent in, this same tee should be used as it is pictured.

View attachment 48324

I hear ya on the AAVs. I just don't see another option without another hole in the roof. . I just had the roof redone last spring and really don't want to go that route. I did get in there about an hour ago and there's no way I have the clearance to connect to the existing vent above the ceiling. I even considered venting through the gable end wall and while I have all the necessary clearances under IPC to do that, I'm really not liking the idea or how it will ultimately look.

Only other option I can think of would be to cut the existing vent just below the roof and slip on a 90, run a new vent for the toilet trap up the wall to the left of the flange, change the 1.5" for lav & shower to 2" and vent that up through that wall and connect everything in the ceiling.

After measuring again, I only have 4.75" of space between the top plate and the roof, so getting a 2" san tee in there @ 4.562" in height is just asking for mistakes, but cutting that vent and adding a 90 @ 3.969" in height I think might just be doable.

Would this work better?

 

[Twowaxhack]

I appreciate the reply and info. I had considered running a vent up through that wall, but the existing vent is on the exterior wall with a low pitched roof. there's only about 5" of clearance between the top plate and the roof. Not sure I'd have the clearance to connect there. That's ultimately why I settled on the AAV. The AAV I'm looking at is rated for up to 24 DFU's on a stack so I thought it would be okay. This is it.

I'll see if I can get in there today to determine if running a dry vent through that wall and connecting the to existing will work. Thanks again.

I see multi million dollar beach houses with AAV all the time. It’s whatever your code allows then a choice after that for you to make.

Some people subscribe to fewer roof penetrations the better. Some like the zero maintenance of the open atmospheric vent. I see both sides of the coin. I do see them fail and when they fail it stinks up the joint……

It’s not healthy. So I can see the point of health reasons to avoid AAV.

personally I like loop vents or combination waste and vents. Over sizing the piping. Works well and there’s little maintenance other than a jetter once every 25 yrs.