Horizontal Wet Venting 2 Toilets - Virginia

[Tomato]

I’m in Virginia under IPC and am building the plumbing for these back to back bathrooms in my house. I haven’t done much with wet vents so wanted to get options on this. It’s a lavatory at the far end with a dry vent (2”). That goes through a combo wye to the first WC (wall mounted) with a flat 3x3x3 wye. Then it goes to the nearest WC (normal toilet) with a flat 3x3x3 wye. Will this work?

Thanks,
Chris

 

[wwhitney]

This is allowed by the IPC. "Flat" of course means that both inlets have 2% slope downstream. [Well, the IPC allows 1% slope on 3" drains.]

Cheers, Wayne

 

[Sponsor]

 

[Jeff H Young]

looks good I dont think you need a 2 inch dry vent but the wet vent portion upstream of the w/c until the lav santee should be 2 if you wante you could continue with 3 inch as you drew it for clean out purposes

 

[wwhitney]

looks good I dont think you need a 2 inch dry vent but the wet vent portion upstream of the w/c until the lav santee should be 2 if you wante you could continue with 3 inch as you drew it for clean out purposes

Actually, the IPC allows a 1-1/2" wet vent to carry 1 DFU. So both the lav drain up to the first wye and the lav vent could be 1-1/2".

But I figured 2" is better, since you and I both work under the UPC. : - )

Cheers, Wayne

 

[Jeff H Young]

I saw a ipc drawing showing a 2 inch for 2 toilets but now i realize there was a lav and a tub on the drawing I saw so that pushed it up in size . so good call 1 1/2 would suffice for Virginia looks like he has 2 inch there but Id prefer the 2 inch on at least the wet vent too . but I guess his code works

 

[Tomato]

Thank you for the help! Due to layout constraints I ended up changing the design slightly to this. It has the 2” lav at the far end and this will vent through roof. The 2” lav drains into a wye which goes to 3”. The back part of the 3” will have a clean out. Then both WCs go though 3” wyes. Will this still work?

 

[wwhitney]

Will this still work?

I understand your picture to show that, starting at the 3" cleanout and going downstream, you have:

3" cleanout
3x3x2 horizontal wye receiving the lav drain (no other fixtures)
3" horizontal wye receiving a WC
3" 45
3" horizontal wye receiving a WC

If so, that connectivity is fine for a dry vented lav to wet vent 2 lavatories under the IPC.

Do you have at least 1% slope on the 3" drain between the two WCs? The downstream end of your picture looks surprisingly tight to the subfloor, but pictures can be deceiving on such things.

Cheers, Wayne

 

[Tomato]

Thank you! I believe the drop is ok. For the 3” I’m shooting for between 1/8” to 1/4” per foot. Between the two green lines from clean out to entrance to downstream wye is 5 feet and the drop is 1 1/8 inch.