I recently had some custom cabinets installed, however I didn't really think too much about the new location of the sink and venting when I had them created. Now I'm a bit worried that I'm in a bit of trouble.

I had my old utility sink connected to the same vertical stack that my bathroom sink and washing machine were connected to as you can see in this picture:


With the new cabinets, I thought I'd just connect the new drain line to the existing line that run below the floor as seen in this picture:


Where the black rectangles indicate where my new Y connection would be, come through the floor (indicated by bright flashlight), then through the joist, connecting to the Y. Essentially all I'm doing is moving the old sink connection Y to the same pipe but on a horizontal slope about 3 feet from the original.

I'm worried about passing code inspections around venting. I've asked if Air Admittance Valve's are code acceptable but haven't heard back yet.

Can anyone tell me if, without the AAV, would I still be within code for my new connection?

Here's what the new laundry room looks like:




-Jeff in MN

 

You can't come out of the floor into the cabinet as you've stated unless you use an AAV. You'd be creating an 'S' trap, which are prohibited by code.

You'll have to check your local inspector about allowing an AAV. They are generally considered inferior to an atmospheric (roof) vent because they are mechanical and can/will break eventually.

You'll also have to consider extra bracing for that joist you'll be notching to fit the new wye into.