Adding new bath, questions

[Weswsimpson]

Hello, I'm adding a new bath to an existing house, converting a small bedroom to a master bath. The house is slab on grade so I will be cutting the slab, running the pipes and connecting to the yard sewer line that runs out to the street main. I'm wet venting the sink, tub, and shower. The toilet connects to the soil stack separately. I have two questions:. 1. Should the toilet connect to the soil stack above or below the drain for the sink, shower, tub? 2. I often see pictures of the drain connecting to the sewer at 45 degree angle, is this necessary, or can I connect flat with a combo y?

 

[Weswsimpson]

Hello, anyone have any thoughts about my questions?

 

[Sponsor]

 

[James Henry]

The best way is to tie the combination lav, shower and tub drain into the toilet drain before it enters the stack but following your layout I would tie the toilet into the stack above the other drain. The toilet wont siphon the other fixture traps because they are wet vented, if you put the toilet below the other drain you would be draining into the toilet vent stack which is illegal. their are other ways to plumb this but this is how I would do it for your layout.

 

[Reach4]

An alternative is to connect the toilet above the other drain using a sanitary tee. The stack is a dry vent into the top of the santee. This presumes that there is no drainage into the stack before this.

It is not clear where the existing drainage joins the new stuff. Is that in the yard?

Arizona has places that are UPC and some that are IPC code. Your plan could satisfy both. There are details to be worked out.

 

[Weswsimpson]

The best way is to tie the combination lav, shower and tub drain into the toilet drain before it enters the stack but following your layout I would tie the toilet into the stack above the other drain. The toilet wont siphon the other fixture traps because they are wet vented, if you put the toilet below the other drain you would be draining into the toilet vent stack which is illegal. their are other ways to plumb this but this is how I would do it for your layout.

 

[Weswsimpson]

Thanks for the answers! I'll connect the toilet above the other drain. Attached a revised drawing.

 

[Reach4]

https://www.tucsonaz.gov/pdsd/building-codes says Tucson has adopted IPC. https://wabo.memberclicks.net/assets/pdfs/Plumbing_Venting_Brochure_2018.pdf may help.

I am not a plumber.