Trying to plan out my kitchen/pantry remodel, but trying to decide how to best vent everything. This is a 1915 Craftsman Bungalow, to give an idea of age and possible past....
What I have is 2" PVC coming off the main 4" PVC main waste line, it only feeds these two rooms. The 2" pipe rises about 4' off the main stack, turns and goes about 15' then Y's off with about 8' of pipe going to the pantry and another 16' or so going to where the kitchen sink is. The drain/waste line stays at 2" to each point. Problem is due to window location in the kitchen I can't see any feasible way to install a proper vent for the kitchen sink. When I bought the house, the pantry was used as a laundry. I moved that to the basement and am going to be reclaiming the space as a pantry once again.
With the current setup, the only vent for both of these rooms is a weak attempt at an island vent under the kichen sink. I say weak attempt, because clogs aren't uncommon due to the lack of a vent.
My plan is to move the dishwasher to the pantry and install a sink in there as well. In the kitchen I will be installing a farmhouse sink and either doing a proper island vent or an AAV. For the pantry, there is actually an unused 1-1/2" cast iron vent stack in the wall. I can't inspect it entirely because it's covered by plaster and cabinets, but it has been capped with a rubber cap on the outside. At first thought this would be perfect to vent the pantry, but it sits directrly under a 2nd story deck and I don't really have anywhere to move it to.
So I guess the question is what is the best method to vent both of these rooms? An AAV or island vent setup in the kitchen? There again I can't run a stack out the roof as the area is in a box out and there are windows on all 4 sides with no clearance between studs. Moving to another wall is not an option. For the pantry, do I go with the 1-1/2" cast that is in the wall and live with possible sewer gasses under the deck? It's possible I could install try to follow the decks framing and at least get the pipe away from the center of the deck and up a few more feet. Or do I go with another island vent setup or AAV? Any other suggestions/ideas???