I just want to make sure my plan for moving some plumbing around for a kitchen remodel is sound. I am moving the kitchen sink from the wall to an island. I've never done a loop vent before and all the examples I've see online have the vent going to a different area than the drain.
Like this: Since I am moving it from the existing sink that goes strait down from the vent, I'm not sure if that is a problem. Here is my current setup: I'm not sure why there are 2 drain pipes converging to one in the basement all of them are 2" including the one they end up in that goes under the floor. Any chance I could combine them to simplify things? Here is what I am thinking for the new setup I kept the 2 drains separate for simplicity: Does it matter how far above the vent line is above the drain line when they hit the main vertical pipe? I'm also moving my washer which requires running a horizontal vent. Any issue with moving that the way I've drawn it? Any advice is much appreciated.