The combine outlet may cause insect and backflow grease water from sink outlet go into your washer.

Also the pipe via wall will mess up your kitchen cabinet. The possibility of leaking at corner cabinet will be a issue too.

The other side of L corner is your stove area? Where are you going to put your gas tank? Try not to mix wet kitchen and washer.

I guess if no choice that is the way.

Check with your contractor the pipe size too. Dont underestimate the water flow from washer’s pump. Go to electrical shop and ask the recommended drain pipe size.

The problem with water trap is they cut the flow volume.

This post has been edited by chamelion: Feb 17 2020, 12:10 AM