I have a kitchen sink on the front of the house that I vented along the slope of the vaulted ceiling and then back down the other side where it ties to another drain and the vent on the back side of the house. The vwent will fully drain on both sides of the house, so as far as functionality there is no question that it will work. My inspector will pass it if I can give him code refrences that allow such venting. I have no idea where to start, and at this point don't have access to the code. Is there an allowance for venting this way in the international plumbing code?