Connect to water closet trap arm?

[OttoG]

Is this layout code compliant in CA? In particular the connection to the water closet trap arm.

Thanks

 

[wwhitney]

No, one of the lav or shower dry vents would need to be 2". Because by connecting the lav/shower to the WC fixture drain before it reaches the stack that could dry vent it, you now need to wet vent the WC via that lav or shower. And a WC needs a 2" dry vent.

If you make that change, the layout is OK assuming the distance limits are met. 2" shower trap arm (trap to vent takeoff) needs to be no more than 60" in length and 2" in fall (if the segment from shower trap to shower/lav combo meets those limits, you could delete the shower dry vent and let the lav wet vent the shower). And 72" maximum from closet flange along the pipe to the vent takeoff, which is the 3x3x2 combo in the wet venting scenario.

Cheers, Wayne

 

[Sponsor]

 

[OttoG]

No, one of the lav or shower dry vents would need to be 2". Because by connecting the lav/shower to the WC fixture drain before it reaches the stack that could dry vent it, you now need to wet vent the WC via that lav or shower. And a WC needs a 2" dry vent.

If you make that change, the layout is OK assuming the distance limits are met. 2" shower trap arm (trap to vent takeoff) needs to be no more than 60" in length and 2" in fall (if the segment from shower trap to shower/lav combo meets those limits, you could delete the shower dry vent and let the lav wet vent the shower). And 72" maximum from closet flange along the pipe to the vent takeoff, which is the 3x3x2 combo in the wet venting scenario.

Cheers, Wayne

Thanks Wayne,
I would have to open the walls to get to the vents. The rest I can access from below. The bath is over a garage in a split level. The existing is hanging below the joists and I am trying to get it inside the joists so I can drywall the ceiling. I can probably pull this layout off. Would it comply?

 

[wwhitney]

Yes, that's fine, as long as the 3" Trap Arm (including the vertical portion from closet flange to closet bend) is 72" or less. Then the 2" stack dry vents the WC. The 3x3x2 Combo could be a 3x3x2 san-tee if it fits better; if it doesn't matter, the combo seems to be preferred.

Cheers, Wayne

 

[OttoG]

Yes, that's fine, as long as the 3" Trap Arm (including the vertical portion from closet flange to closet bend) is 72" or less. Then the 2" stack dry vents the WC. The 3x3x2 Combo could be a 3x3x2 san-tee if it fits better; if it doesn't matter, the combo seems to be preferred.

Cheers, Wayne

Hi Wayne,

Thank you for generously sharing your expertise. I am soooo appreciative. Believe me, ignorance isn't always bliss.

Happy New Year

Tony