When a water closet (toilet) is wet vented via a lavatory (sink) in the same bathroom, does the Uniform Plumbing Code (UPC) limit the maximum vertical drop beneath the water closet (WC)? Or do any California amendments limit it? Here is an illustrated example - in the first approach the WC drops to grade (~30" below the subfloor), then runs horizontally to the combo with the lavatory that serves as the wet vent. The horizontal distance between...
Originally asked by tom on Stack Exchange (diy) (CC BY-SA 4.0).
