Add Kitchen/Wet bar sink, can I Connect to this drain?

[Teezie23]

I’m currently finishing a basement, adding a wet bar with a kitchen sink.

There’s a 4” drain, coming from the upstairs, going into the basement floor, right where the sink is going. (Pictured)

My question: can I connect into that 4” drain, for the kitchen sink, with a 4x4x2 schedule 40 Tee?

is there any concern with toilet water water coming down that pipe, and getting into the T for the kitchen sink?

obviously, I will have a trap for sewer gas, but is there any concern with the upstairs waste water getting into the sink drain?

Anything else I could / should do to make this code?

also, I assume I would need a Studor vent under the kitchen sink, since there’s no place to vent up to.

hopefully this pipe would work, there’s really no other place I can tie into.

 

[breplum]

Make sure you can cut the drain in low enough for a sink. Usually 16" AFF for centerline unless it is a deep sink.
You can NOT just cut in a Tee without adding a plumbing vent. The vent can tie in to any existing vent down there on that floor or higher floors or exit the building and travel up through the roof. (broadly speaking).

 

[Teezie23]

Make sure you can cut the drain in low enough for a sink. Usually 16" AFF for centerline unless it is a deep sink.
You can NOT just cut in a Tee without adding a plumbing vent. The vent can tie in to any existing vent down there on that floor or higher floors or exit the building and travel up through the roof. (broadly speaking).

I was planning to use a Studor Vent / Cheater Vent, since there’s no vent leaving the basement anywhere.

But my main concern, is can toilet water, coming down that drain, make it into the Tee , and get into the sink drain...

 

[breplum]

The ptrap at the sink would absorb splashing. As long as you don't have a sewer clog downstream, you'll be ok with the magic vent AAV.
It would be better to cut out the 45 deg. elbow, make it a wye and have your new sink branch come off lower.

 

[Teezie23]

The ptrap at the sink would absorb splashing. As long as you don't have a sewer clog downstream, you'll be ok with the magic vent AAV.
It would be better to cut out the 45 deg. elbow, make it a wye and have your new sink branch come off lower.

oh, that’s perfect, I like the wye much better, that would make me more comfortable.

Thank you!

 

[Teezie23]

The ptrap at the sink would absorb splashing. As long as you don't have a sewer clog downstream, you'll be ok with the magic vent AAV.
It would be better to cut out the 45 deg. elbow, make it a wye and have your new sink branch come off lower.

I’m finally getting back to doing this.

unfortunately, I can’t cut into this pipe above the clean-out, or the sink rough in would be too high off the finished floor.

is it acceptable to remove the clean-out plug, and just add a 4” threaded to 2” female adapter, then use what is currently a clean out, as the spot to access the drain?

i found all the pieces, it would work out well for placement, I don’t don’t know if an inspector would doing this since removing the cleanout...?