Wye installed for sink drain

[DanielD]

I hired a plumber to rough in plumbing in a drain pipe to add a utility sink. He installed a wye and I think it needs to be a sanitary tee. I just wanted to query the group here before bringing it up. Many thanks, Daniel (pics attached)

 

[wwhitney]

What drainage, if any, is coming down the stack from above? If there's no drainage from above (unlikely), then the stack could be your sink vent if you use a sanitary tee instead of a wye, and the trap is close enough so that the trap arm drops at most one pipe diameter from the trap to the san-tee.

But if there's any drainage from a story above, then you can't use the stack to vent the sink. So you'll need some other venting, either a dry vent that ultimately goes through the roof (but can connect to an existing dry vent at 6" above the flood rims of all the fixtures involved), or an AAV. And then connecting the sink drain to the stack with a wye is fine, and perhaps slightly preferred.

Cheers, Wayne

 

[Sponsor]

 

[Jeff H Young]

A wye can be installed for a sink but that's an incomplete build . if he installs a santee on the 2 inch and vents it out properly that works but it needs vented or an AAV .
So the wye is a beginning and I can't guess what he is doing with it but he could be on track

 

[DanielD]

Thanks for all of the help. That stack does drain a bathroom above as well and continues through the roof as a vent. I had concerns about venting, but he did not seem to share it. From the above comments, it sounds like I could make it work with a sanitary Tee and AAV in conjunction with the sink drain? This is an older commercial building that I recently bought. Upstairs is not currently in use. I am occupying the bottom level for work and personal use. Many thanks for any input. Daniel

 

[wwhitney]

it sounds like I could make it work with a sanitary Tee and AAV in conjunction with the sink drain?

Easiest is to use an under sink AAV kit, then at the wall the sink drain is already vented and can take the appropriate path to the wye.

Or you can use a san-tee (in the usual orientation) at the wall behind the sink, with the AAV at the top, the trap arm coming in the side as usual, and the outlet again running to the wye inlet.

Cheers, Wayne

 

[DanielD]

Thanks Wayne! Sounds like a plan. Best, Daniel