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I want to install the plumbing for a washing machine on a new wall that previously had no plumbing. I would like to use an AAV to vent the drain, and I'm wondering if my schematics will work, or if there are any suggestions. This mudroom is on a concrete slab. On the wall to the left and the wall behind the viewer is crawl space for the rest of the house, which sits about 20" higher than this room. Also, my plan is to install a recessed wall box for the AAV with a removable grill for airflow and access.
 

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Master Plumber
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IPC the AAv needs to be on the vertical stack of the horizontal discharge arm, above the flood rim ( Washer valve/ box drain) also if this is a new branch it needs to be in 3 inch on a 2 inch trap. and also what or where are you tapping in to.?
 

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Running supply lines in an outside wall is not a great idea.
I'd at least use PEX and run them in front of the insulation or better yet build that wall out, simple 2 X 2's attached to the studs will work.
AAV would need to be exposed or have an access panel.
 

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I suggest you double the wall. Put all plumbing in the new interior wall. A washer is a pumped discharge you really need to vent it to a vent or out the roof separately.

The washer drain should be 2 inch. The stack or building drain must be 3 inch pipe.

AAV's on a pumped discharge fail quickly.
 

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Like Ghostmaker said, washing machines are one of the few drains where significant positive pressure is introduced. AAVs can work great in a lot of situations, but washers aren't one of them. You really need a vent that allows air to be pushed out as well as let air in.

Some people have their washer draining into a laundry tub which will relieve the positive pressure and let you get away with an AAV (not speaking of code here, just function), but it's not terribly elegant.
 
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