[btipton]

I'm putting a kitchen sink next to an outside wall. The wall is 2x4 framing, and sits on a 2x10 rim joist. My question is, do I cut the hole for the drain through the wall cavity, or can I go through the floor, since it will all be enclosed anyway?

My concern is that the wall is too narrow for the drain (1.5 inches for rim joist from a 3.5 inch wall thickness)

Thanks,

Bob

[speedball1]

Hey Bob,

You do realize that in addition to the drain the sink will have to be vented with a pipe that runs to the roof don't you? However, there's a way around that that will allow you to keep the drainage inside the house and still vent the sink.
OK, Here's how I would run your installation.
Sink drain to "P" trap, a upright tee directly after the trap with a AAV,( Air Admittance Vent, see image) installed in the upright branch of the tee, a turned down ellbo to take the drain through the floor to connect into the house drainage system. Good luck, tom

[btipton]

Thanks for the quick reply. I'll check with the inspector to see if AAV's are allowed locally. If they are, that'll definitely be what I would use for the vent. I wasn't as worried about running the vent up the outside wall, since there's no rim joist in the way at the top of the wall.

If I read your answer correctly, then I can run the drain through the floor, rather than having to take it back into the wall, correct?