I'm installing a utility sink in the garage. I'm teeing into the laundry drain on the other side of the wall. I undersatand I should install an AAV just beyond the p-trap as so I won't suck the laundry p-trap dry that is just upstream from that point.
However.. here's my delemma. The sink is 36" mounted to the wall. I'd rather not go any higher than that. It's tub is 14" deep. That leaves me with 7 or so inches of wall (floor joist)that I can place the drain. The rest below is brick and I don't want to mess with that.
I have very limited space to place this AAV, so my plan is to 45 the tee connection, then insert a 45 elbow, then place the AAV on top of that. The problem is.. now it's butt up against the bottom of the tub. I want to stay in code with this and have it 4" min above the trap weir.
I think there's a simple answer here, but damn if I can think of one. Anybody?

"I'm installing a utility sink in the garage. I'm teeing into the laundry drain on the other side of the wall. I undersatand I should install an AAV just beyond the p-trap as so I won't suck the laundry p-trap dry that is just upstream from that point."
STOP RIGHT THERE! Define "laundry drain"! Are you referring to a washer stand pipe? Another laundry sink that you're connecting to the drain? Connecting to a vent off the fixture you're describing as a "laundry drain"?
I'll be glad to answer once I know what I'm working with. Regards, Tom

Sorry, I guess I need to mention this is a new home and it's own laundry room. Yes. Correct. The washer drain stand pipe. It comes down the wall, goes through a trap, and straight down the wall horizontally to connect to other larger drain pipes. This is in the crawl space.
Now I don't know how the stand pipe is vented. All I can tell you is there are no other sinks and there is only the wall to separate where I want to place the sink in the garage.
As the washer drains, it will be going right past where I want to tee in at. Approx 6' downstream. I do need a vent at my sink right? Or are you seeing a problem here?
BTW, the sink drain pipe I'll be installing through the wall is 6" higher than the "laundry drain" so it will be pointing down when completed.
John.

The sink install in the garage worked out good. No problems. I'm finding some local codes do not want anything sharing the laundry drain. In NC that doesn't seem to be a problem. My drain turned out to be just inches before the vent stack where I teed into laundry drain. I used the studor valve just past the trap. This large sink drains just perfect. Couldn't be more happy. Since the water heater is in the garage also, hot water is almost instant.
I recommend the wall mount sink. Just brace the wall studs to give it all the support it needs. A 19$ backsplash panel at the big store completes the look.