: I am installing a new bathroom in my basement, and have to place the pedestal sink approx 5 feet away from the existing roughed in drain pipe. I also have to turn a 90 degree corner to reach it. What is the recommended slope for the drain pipe? I have approx 16 vertical inches to play with. I assume this is enough, but I want to avoid excessive drainage noise from too steep a slope (I assume fast draining water will make more noise...).

1/4" per foot will do it.