Hi everyone, I am trying to figure out DWV plumbing layout in a 2 x 4 wall with the least amount of holes in framing members. The plumbing is for an upstairs bathroom with a double vanity where the drain/wet vent is already plumbed to the far right of both sinks (instead of in between). I am under IPC. The drain/vent is about 6'4'' from the furthest sink which means it is just 4” too far to have a 1 1/2” interconnecting trap arm run between the two sinks "911.2 Connection at the same level. Where the fixture drains being common vented connect at the same level, the vent connection shall be at the interconnection of the fixture drains or downstream of the interconnection.". I am hoping the interconnecting trap arm can still work if I can run a re-vent between the two sinks (Pic #1)?. I have another layout that I believe works and might be preferred (Layout on Pic #2), but this layout requires a lot of holes in the 2 x 4 wall. I included some alternative layouts that I thought could possibly work which require fewer holes. Layout #3 was suggested to me by an experienced, but non-licensed plumber. Do any of these layouts work? Any other changes/recommendations? Every 2 x 4 stud is already doubled and regardless of the layout chosen I plan on using 1/2 or 3/4'' plywood across one side of the entire wall for shear strength. The wall is load-bearing in that it will be a small 5' x 10' loft/upper room in a kids bedroom. Thank you.
Pic #1: interconnecting trap arp w/ revent
Pic #2: I believe works, but requires a lot of holes
Pic#3: Recommending by plumber (unlicensed).
Pic #4: use of double fixture fitting or double San-tee with AAV attached above.
Pic #1: interconnecting trap arp w/ revent
Pic #2: I believe works, but requires a lot of holes
Pic#3: Recommending by plumber (unlicensed).
Pic #4: use of double fixture fitting or double San-tee with AAV attached above.
