Wow, been a while since I've been on this awesome forum. Decided to add a small bar sink in a "butler's pantry" we're working on, stealing the cold water from a powder room toilet that is just on the other side of the wall where we're planning to put the sink.
But in the process, discovered the toilet does not have a vent as I understand it. (Toilet works fine, BTW).
So am thinking of adding an Air Admittance Valve on the bar sink, that would act as a wet vent for the toilet. Could actually also go up with a roof vent, but would have to tear out a bunch of sheetrock, make a bend and go thru a double roof....
So here is the general idea of what I think would solve the problem - NEW PROPOSED CONNECTION IN GREY: - Will this work to vent both toilet and sink?
(I took the liberty of modifying someone else's diagram I found on the forum I hope that's OK!)
Comments, Advice welcome!