Horizontal Wet Vent

[Marchiano]

Is one of these plans better than the other for the tub? Wye farther down vs. double wye with reducer. Thanks.

 

[Tuttles Revenge]

The controversial flat double wye!! Most if not all jurisdictions won't let you install a double wye on its back because both of the inlets don't have grade. UPC also wants the toilet to be the Most downstream fixture in a H-Wet Vented system, so your tub would need to be either downstream and vented separately or connect upstream of the toilet and wrap around.

 

[Sponsor]

 

[Terry]

I never use double wyes on the horizontal like that. I will use two wyes, which allows me to tilt them to pick up my 2% grade.

 

[Marchiano]

The controversial flat double wye!! Most if not all jurisdictions won't let you install a double wye on its back because both of the inlets don't have grade. UPC also wants the toilet to be the Most downstream fixture in a H-Wet Vented system, so your tub would need to be either downstream and vented separately or connect upstream of the toilet and wrap around.

Good to know. I actually already have it plumbed like that but the tub trap arm might end up being too long once I put one in so I was hoping to make a shorter route. Looks like I’ll be separately venting it. Do you happen to know if a separately vented fixture is allowed to drain into the toilet’s arm (within a wet vented system) under the UPC or does it absolutely have to be downstream? I know it’s allowed under Canadian code.

 

[Tuttles Revenge]

Canadian code also wants the toilets most downstream. But they allow a double wye. Any bathroom fixture within the bathroom group may connect within the horizontal wet vented system even if its vented on its own. There is no limitation to the number of vents a fixture or system may have.. just odd. (I've had to argue this with inspectors)