Hey all, Working through this bathroom remodel. Our subfloor is 3/4" plywood and there was either a 3/8 or 1/4 underlayment placed on top of that as a base for the tile. I'm likely going to place 1/4 concrete board on top of the 3/4" subfloor and then apply ditra heat and tile over it. Regardless of the base layers, how do I handle this? I was thinking that I just need to cut off the current flange, glue in PVC and leave it extended above the surface, let tilers do their thing then come back and trim it out. However, I'm not sure I have enough pipe to attached a coupling and extend the small section of pipe if I cut out the flange. I've cross posted this in framing to address the plumbers installation of the drain where he apparently drilled into the floor joist, then realized what he did and moved the hole.

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