Vanity Conundrum

[Jcheech]

Before I get down to business wanted to say thank you in-advance for your time and suggestions. Your responses are very much appreciated. Also, wanted to dive on my sword for making a bad rookie mistake in laying out this vanity and cue some well deserved laughter from the group. Here's my issue:

We picked out the vanity illustrated below and neglected to refer to the rough-in specs for the drain.

As luck would have it, the wall inlet for the wast line falls 16" above the floor. Just high enough to be cut into the back of the vanity, but too low for us to install the P-Trap without butchering the cabinet:

Here are the vanity specs - the ones I should have referred to before closing the walls:



My idea for a solution here is to install the P-Trap within the "General Roughing-In Area" depicted in the specs, run the horizontal line to a Sanitary Tee, (air-gap 4" above the trap) and back around to the wall inlet. Below is a picture of what I came up with:

I think this is the proper way to do this without destroying the $1,500 vanity cabinet.

1. Please opine as to the reasonableness of my solution.
2. Sink tailpiece is 1-1/4. Was going to adapt to 2" at the J-Bend and continue with 2" waste lines.
3. I think the Air Vents are 1-1/2". Will adapt as necessary.

Thanks again for your opinions.

 

[Kreemoweet]

Just open the wall and move the drain outlet to where it needs to be. Sheesh. No need to
follow up one error with another, just to compensate. Drains are moved All The Time.
It is a standard part of "remodeling". Your proposal is just another ugly DIY hack.

 

[Sponsor]

 

[Jcheech]

Thanks for your response, Kreemoweet. I guess good plumbers are born not made. To be a condescending douche bag, however, is an acquired skill. Kudos.

 

[Terry]

What do you have coming out of the wall? Some plumbing from the 60's was 1-1/4" galvanized. Newer stuff was 1-1/2" plastic.
If the line is vertical in the wall, it's pretty easy to cut and raise a santee. You can add the AAV as a fix if you don't want to touch the wall. If you are at 16" now though, it still looks like you will have to notch the cabinet going the AAV route.

 

[Jcheech]

Terry, thanks for your thoughtful reply. The home was built in 1970 and the waste line looks to be copper. It's likely 1-1/4", but I'd have to confirm. The fitting protruding from the wall is sweat x 2" male. There is a bushing on it to pair down to 1-1/4" for the P-Trap. Inside the wall the line runs horizontally and ties into the stack, maybe a foot or two to the right.

Would it be less of a "hack" if I opened the wall, cut out the elbow and instead sweated a 90 to get it vertical, raise it up, then come out into the "rough-in zone" per the specs?

Thanks, again for the productive response.

 

[Terry]

If you raise the horizontal trap arm, you will either need to add venting at the level it comes out, and revent at 42", or add the AAV.
Once you raise it above the venting, it becomes an S trap that will siphon. We're having a flurry of these with the new cabinets, and complaints of sewer smells in the homes.