Bathroom remodel and addition

[OptimisticDIYer]

Hi everyone. I’m new to this forum and DWV plumbing so sorry if I make a fool of myself. I am currently in the process of remodeling a bathroom and adding another in the finished attic. I will be removing the cast pipe and replacing with PVC. The space is pretty small so I had to get creative on how things would fit. I tried my best to do a drawing to capture the plan. My question is, is this up to code? Specifically the double wye fitting for the toilet and lav on the 1st floor, and the offset of the stack for the horizontal branch of the 2nd floor bathroom I'd like to add. I’m not sure if this is even considered an offset since only one other branch goes to it. If it is an offset though would I need to vent it since the double wye is within 24”? Trying to stay up to IPC code. Any thoughts and advise would be welcome!

 

[Terry]

The basement bath looks fine, and the offset for the upstairs bathroom is fine.
The attic bath of course we can't comment on yet. The waste for the attic bath can't use the vent for the 2nd floor bath.

 

[Sponsor]

 

[OptimisticDIYer]

The basement bath looks fine, and the offset for the upstairs bathroom is fine.
The attic bath of course we can't comment on yet. The waste for the attic bath can't use the vent for the 2nd floor bath.

Thanks for the quick reply!

So are you saying the attic bathroom can’t use the offset into the top of the double wye as waste flow? I need to get the waste down the offset. I can add another vent just before the long sweep to horizontal on the offset if that solves the issue.

Both the lav and toilet on the 1st floor are vented individually which would connect to the vent stack.

 

[Terry]

I think I need the full diagram of what you're doing.
Once something is a vent, it stays a vent all the way through the roof.

The double wye you mention shows a toilet that has a vent and a lav with a vent.
The waste going down the center looked fine.

 

[OptimisticDIYer]

I think I need the full diagram of what you're doing.
Once something is a vent, it stays a vent all the way through the roof.

The double wye you mention shows a toilet that has a vent and a lav with a vent.
The waste going down the center looked fine.

 

[OptimisticDIYer]

I think the full diagram would look something like this

 

[John Gayewski]

View attachment 80605
I think the full diagram would look something like this

What you drew is fine in theory. In practice I'm sure there are some details you'll come to that make it less clear. Your on the right track though.

 

[OptimisticDIYer]

What you drew is fine in theory. In practice I'm sure there are some details you'll come to that make it less clear. Your on thr right track though.

Thanks John and Terry. I was really just wanting to make sure that I could do that horizontal offset for the attic waste line. I really appreciate the advise and confirmation!

 

[wwhitney]

No tubs or showers?

Only the fixtures need venting. So you don't need the vent section that is the continuation of the stack above where the upper lav and WC join, since they are separately vented.

Cheers, Wayne

 

[OptimisticDIYer]

No tubs or showers?

Only the fixtures need venting. So you don't need the vent section that is the continuation of the stack above where the upper lav and WC join, since they are separately vented.

Cheers, Wayne

Good to know! Thanks for clearing that up Wayne. The tubs and showers are on a separate waste and vent stack.