Shower and toilet on same vertical drain?

[northwoods]

Is it OK for the shower to be on the same vertical drain/vent line as the toilet? Seems risky, if toilet clogs. Could back up into shower. But I can't figure out any other way to vent the shower. The shower line is the 2" blue one. The toilet stack is 3".

My apologies if this is a duplicate posting. The earlier one didn't seem to make it!

 

[Tuttles Revenge]

Typically that would be a Vertical wet vent. However, from my brief reading of wisconsin plumbing code. The vent from a floor mounted toilet is prohibited from being used as a wet vent for another fixture. They restrict vertical wet venting to only Wall Mounted Fixtures. However, horizontal wet venting is an option for you if you have the space to do it.

A layout drawing / plan view of the fixtures and the drain location would be helpful in determining a way to get this done.

https://dsps.wi.gov/Documents/Programs/Plumbing/SBD8869_DrainVentDesign.pdf

Page 54 starts their wet venting rules

 

[Sponsor]

 

[northwoods]

I had read the wet vent part of the pdf you sent a link to. When I read this (page 58): "Any two fixtures may be combined in this type of installation, but the higher fixture drain may not serve a water closet." I thought a shower could be the "higher fixture" and the lower fixture could be a water closet. But now I see that by "water closet" in this sentence they must mean only wall-mounted ones.
So thanks for straightening me out. I'll have to figure out another way to drain/vent the shower.

 

[Jeff H Young]

put a 3x3x2 wye on top of the combo and finsh off the toilet , and on the 2 inch put a 45 then come up put your 2 x 1 1/2 x 2 santee for the shower bring 2 vents throught the floor and join them togeter 6 inch min above the toilet rim so maybe 2 ft or more , easy enough

 

[northwoods]

put a 3x3x2 wye on top of the combo and finsh off the toilet , and on the 2 inch put a 45 then come up put your 2 x 1 1/2 x 2 santee for the shower bring 2 vents throught the floor and join them togeter 6 inch min above the toilet rim so maybe 2 ft or more , easy enough

Intriguing idea! Thanks. As it happens other issues have raised their unwanted heads. My crawl space is only about 24" (!@&?) and so there isn't enough vertical room either for the original stack I'd drawn or (I think) for you idea, as the combo wye takes up 11" vertical by itself, and the sani-tee for the toilet another 6 1/2".
Fortunately, I believe I've found yet another way. I was concentrating so much on everything flowing downhill toward the exit of the basement that I overlooked the possibility of sharing a stack with one of the "uphill" sinks. But as it doesn't matter what direction the wet vent goes before it hits a stack, there's room for it to go "backwards" at the 1/4" downslope per foot until it drops down through the stack and then heads "downhill" forwards.

Thanks, again, for your response.

 

[Tuttles Revenge]

I would be considering how to implement horizontal wet venting. It would be possible to plumb the tub traditionally, then downstream connect the toilet that then connects to the main drain.

 

[Jeff H Young]

based on the drawing provided i can only recomend the 2 dry vents if you dont have depth lay a 3x3x2 y in the trench horrizontally to pick up the shower with a 2 inch long sweep to put the santee up to hieght and then vent the 2 together similar to the other suggestion I made.
Northwoods you provided to little info for all i know this 3 inch combi was already set an existing toilet who would know.?
look up 3x3x3x2 side inlet santee mayybe that meests your code?

 

[Tuttles Revenge]

based on the drawing provided i can only recomend the 2 dry vents if you dont have depth lay a 3x3x2 y in the trench horrizontally to pick up the shower with a 2 inch long sweep to put the santee up to hieght and then vent the 2 together similar to the other suggestion I made.
Northwoods you provided to little info for all i know this 3 inch combi was already set an existing toilet who would know.?
look up 3x3x3x2 side inlet santee mayybe that meests your code?

Good thought on the side inlet tee. It is approved and has a diagram on pg 55. It has a caveat that the center line of the side inlet must be above the center line of the larger toilet trap arm. Looks like this is how most are manufactured.

https://www.supplyhouse.com/Spears-P417-338-3-PVC-DWV-Sanitary-Tee-w-2-Right-Side-Inlet?utm_source=google_ad&utm_medium=pmax&utm_campaign=geo_pmax_test&gad_source=1&gclid=Cj0KCQjw9vqyBhCKARIsAIIcLMGj0c-QoapnODtxRLYgw0atxHNmKkpq-PEcSbA7Ymdolb7M5Mj3jkoaAtndEALw_wcB

 

[Jeff H Young]

Yea I dont like those fittings but seems like a solution a 45 or a long sweep should get the trap arm going in the direction needed might need a 22.5 as well

 

[Tuttles Revenge]

The side inlet tee is the exact same as their drawing, just more compact and in a single fitting. Only 1 fixture would likely be used in a bathroom at the same time, so there's little chance that the drain would be overwhelmed.

We almost never have the opportunity to use these, almost everything we do is horizontal wet venting since it was approved in the UPC in 06.

 

[Jeff H Young]

just walked a tract of homes ground work last week slab houses no horrizontal wet venting on the ground work but the second floor had it in the joist bays . down in florida I see real shallow trenches no verticle wet venting . small number of observations.
those side inlets work where you have walls that stack except the trap might be below cieling we used to use a 3 st on bottom and 3x3x 1 1/2 on top with a bushing on top for 2 inch vent and then wet vent the lav