Moving Kitchen Sink Drain

[martin280]

I am moving my kitchen sink as part of a larger remodel. Due to framing considerations, the easiest branch to tap into is a 4" horizontal line (about 18 feet away) that services a second floor toilet and lav. This waste line runs about 10 feet along the second floor, drops vertically (9 feet) to the crawl space under the first floor, then runs horizontally under the first floor for about 12 feet before turning into the ground. I can run the 2" drain line to the 4" horizontal pipe in the crawl space and maintain the 1/4"/12" drop.

My concern is that the kitchen sink will be the lowest overflow point on this portion of the house. Is this an appropriate configuration?

[Terry]

Something has to be the lowest point.


You will want a 2" cleanout under the sink, and a vent going up through the roof.