Venting through a double Wye Tee

[shelski]

I want to re-route my 3" ABS vertical main stack through a wall in the 2nd story bathroom. I want to use a double wye tee. One 45 to be toilet drain, the other 45 to offset the stack to continue through the roof. The center 3" opening would be capped. [See diagram] This is to avoid cutting a floor joist. Is this a workable solution?

 

[Leejosepho]

My guess is that solids from the toilet could catch and build up on the other side of the wye and at least partially clog the vent, but what is the small line connected to that other side? If that is a sink drain, it would probably help keep the vent branch clear.

 

[Sponsor]

 

[BAPlumber]

why not lower your closet bend so the horizontal part passes under the joist. Then use a sanitary tee to connect to the vent stack.

Brent

 

[Master Plumber Mark]

thatt should be ok

I cant remember wether that is called
its either a glorified " stack arm" or a " Stack vent"
or "wet vent"

the 3 inch stack is large enough to vent both
the toilet and the arm going somewhere else....

the double wye like you got will work fine....

I am sure someone out there knows the right
term I am grasping for....

 

[hj]

drain

Most inspectors would turn down the installation because your toilet drain is rising, or dropping depending on which direction you follow the flow, before the vent.

 

[Kordts]

I would flunk it.

 

[Geniescience]

if i read your diagram right, i see on the left a vented stack, and on the right a toilet waste arm, not a branch that has more than one fixture on it. I guess the floor joist is above the double Wye.

It is important in the explanation whether the toilet is all alone or is branched to other fixtures before its pipe connects to the stack.

A drain has to be vented before it goes straight down, and a 45 degree angle down is the same thing. An AAV adds venting before the downward turn. AAV packaging warns you that you have to have real venting too, soon after the AAV.

The way you have proposed it, is worse than if you had proposed adding an AAV to the waste arm.

My saying this is not a recommendation to use an AAV. Many other factors still have to be included. I have not seen your house's plumbing; i do not know your local codes, i am not a master plumber; i don't know whether you have the right to install things that may be acceptable under some lenient codes and not under other stricter codes.

If you had a hand rinse sink near the toilet, and its drain was vented and connected to the toilet "branch" then you would have wet vented the toilet waste arm. Why is there no sink near the toilet?

david

 

[Plumb or Die]

You've got an S-trap there which would allow your toilet to self siphon.

 

[hj]

toilet

The toilet itself is an "S" trap, but that does not mean inspectors would approve that drain line.

 

[Jimbo]

The toilet itself is an "S" trap,inspectors would approve that .

Toilets work BECAUSE they are an S-trap . Hence, they also have a refill operation.

 

[Geniescience]

P trap in Wall Mount toilets. Not S trap. Rear spud. rear outlet. makes it a P trap. Maybe inall cses, maybe only in some.

Toilets work BECAUSE they are an S-trap . Hence, they also have a refill operation.

Some people hate the idea that a typical toilet is an S trap, and that LETS some sewer gases escape during flushing. The refill device is small and ineffective; it cannot stop some small amount of gas from coming out.

Do we all realize what a health hazard that is? SARS and other diseases come through the drain systems when people flush.

I'll go look at how much refill there is in my two different wall-mount toilets. They are hanging on Geberit carriers.

David