Applying IPC 2012 Section 917 - Single Stack Vent

[readytowork]

Can you all show me how IPC section 917 on single stack vents could be used for two bathrooms (tub, toilet, lav) that are stacked on top of one another (first floor, second floor). My appreciation is that the code generally doesn't allow toilets to be in a vertical stack, but that you can have vertically stacked toilets using IPC 917, so long as you have no more than 2 of them. Is that right? I'm trying to visualize how that code section saves on labor/cost and can allow a simplified drain/vent system.

 

[Tuttles Revenge]

I don't fully understand the IPC system for doing stuff... But I can almost guarantee that there is no chance that provision allows the drains from fixtures on one floor to use the vents from the fixtures on the floor below.

*edit* I shouldn't say that.. the IPC has all kinds of weird stuff in it.. its very possible they could use vents as drains from multiple floors.

And here it is. Single Stack Venting

 

[Sponsor]

 

[Jeff H Young]

yep single stack vent IPC 3 inch allows up to 2 w/c . I supose even a basic 2 story might economize on this system . thats the advantage to your code it saves money .
Whats your motivation ? a project ? how many floors what are you thinking of building?

 

[readytowork]

Yes, I'm asking because of an addition I'm trying to do which would have one bathroom stacked on the other. Images attached of my attempt to follow IPC 917. (The stuff on the left is for a washing machine.)

This is slab on grade and the plumbing is in a load bearing wall. As designed, I have a 3" stack which serves the WCs and tub/showers and the lavs on a 1.5" stack.

 

[Tuttles Revenge]

It looks like an oversized stack was the theory behind the Stacked Vent stuff.

Sorry.. I'm just not well versed enough in IPC to have an opinion on this. It hurts my brain to read that code half the time.

 

[Jeff H Young]

its always been totally illegal in UPC code so not unlike tuttles I have no experiance with it . but as you can see minimum stack size starts at 3 inch so the lavs dont work, how hard is it to bring a 2 inch through the first floor put an upright wye below the first santee and run 2 seperate pipes through the floor and revent them ?
definately the larger stack accomplishes the venting thos of us that been taught and prcticed never to wet vent between floors I have some second thoughts but in reality following your code details should work.
why the jog in the line coming off the side inlet santee? that seems wrong also since this is so forieghn to me check into stack size on the w/c it might require 4 inch I dont know and Im not checking it out but share back what you find or decide

 

[John Gayewski]

I don't think 3" works for this. Yet another upc guy that isn't much help with ipc code specifics. Ask your local inspector. They may not even allow such a thing for a residence.

 

[readytowork]

Thanks all. I'll keep asking around to see if anyone locally has an example of a code-compliant setup. I'm interested in knowing how this section applies in practice because it seems an outlier from how most everyone is taught.

 

[Jeff H Young]

looks cool to me but its not in our play book . yea my gut says 4 inch on the w/c stack wouldnt be suprised to hear 3 inch would be legal might take a look and see if there is anything i can figure on sizing.
readytowork the three of us commenting work in UPC code so we dont know the details as well on ipc code

 

[Jeff H Young]

Im back and it looks like a max of 2 toilets on a 3 inch stack if toilets are withen 18 inches of the stack a branch up to 1 1/2 inches can come off the 3 inch going to the toilet . Im still a little suprised maybe you can find more info on whether this can work on your job