Here are pictures of what's currently installed in house.
Washer drain is 2" PVC, drops straight down to S trap, then to Wye.
I think this needs an AAV after the trap.
The slope of the drain lines is too steep at 3/4" or 1" per foot, or can I ignore this
Finally - in upper right of the above photo is this abortion (expanded below)
What else should I do to avoid backups?
You'll notice this drain line has three cleanouts.
(#3 not visible, only a few inches from stack)
When I first moved in, 1-1/2" pipe was sloped backward - G.D bless the *$%$#$# installer
Washer drain is 2" PVC, drops straight down to S trap, then to Wye.
I think this needs an AAV after the trap.
The slope of the drain lines is too steep at 3/4" or 1" per foot, or can I ignore this
Finally - in upper right of the above photo is this abortion (expanded below)
What else should I do to avoid backups?
You'll notice this drain line has three cleanouts.
(#3 not visible, only a few inches from stack)
When I first moved in, 1-1/2" pipe was sloped backward - G.D bless the *$%$#$# installer