Toilet Venting

[Mulligan Stew]

I'm roughing in a 3" toilet drain and want to install a 3x2 wye on the vertical drop, above where the drain turns horizontal. Is this allowed per UPC? I can't seem to find it in the code book.

 

[Reach4]

Yes.

However the toilet is frequently wet-vented by the lavatory. What you propose is good too.

 

[Sponsor]

 

[Jeff H Young]

UPC does have limitations on allowing the vent to run horizontal while less than 6 inches above the flood level of fixture served.
Likely an inspector could fail or aproove based on the practicality of venting properly . We used to do it regularly often without a need but as I found out later on there is discretion . also half the inspectors dont know any better and half dont care .
But I like the Idea of a wye like that to vent with a 45 going up the wall without any horrizontal is good

 

[Mulligan Stew]

Great. Thanks for the confirmations. Yes I like the design and didn't want to have to go back into that frigging crawl space again.