Add Bar Sink to Lav Plumbing

[reynchr]

Hey, folks. Hoping to get some guidance on the best way to accomplish this. I have an existing bathroom sharing a kitchen wall and I want to add a bar sink into the existing drain line while utilizing the existing water sources. My initial thoughts are that I can 'T' off of the existing water sources for the new sink, but I'm not sure how I need to handle the venting for the drain or what fittings are appropriate for this use case. Since I'm looking to add the drain between the existing trap for the lav and the venting that is already in place, do I still need to run an additional vent to the toilet stack? I have linked to a photo of the area, but can add more detail, if needed.

Thanks!

 

[Terry]

When you say toilet stack, do you mean the vent for the toilet? Or is there a toilet above on the next floor.

If there is a toilet on the next floor, then there should be a vent before it hits the 3".

If the 3" is only a vent and the lav is the only thing going down it, with the toilet below, that would be called a wet vent, the lav venting the toilet.
If this is the case, you can add a second Santee there and wet vent one over the other.

 

[Sponsor]

 

[reynchr]

When you say toilet stack, do you mean the vent for the toilet? Or is there a toilet above on the next floor.

If there is a toilet on the next floor, then there should be a vent before it hits the 3".

If the 3" is only a vent and the lav is the only thing going down it, with the toilet below, that would be called a wet vent, the lav venting the toilet.
If this is the case, you can add a second Santee there and wet vent one over the other.

Thanks, Terry!

I may have gotten some of the terminology wrong-- sorry about that. There is only one floor in the home and only the toilet is venting to the vent I labeled as "toilet stack" on my diagram. (There is a bath next to the vertical vent that is currently exposed, but I would have to guess that is vented and drained on its own, yes?)

Just to clarify, when you're saying I can wet vent one over the other, does that mean I can just add a Santee into the horizontal drain branch (..?) and have it vented through the existing vent? Or do I have to run another vent vertically up from the Santee and tie into the vent at a higher level?

Thanks for your advice and sorry for my novice-ness regarding terminology and what not!

 

[Terry]

I would do it on the vertical 3" vent for the toilet.
One arm over the other, both vented by the 3" stack.