I am rehabbing one of my apartments that sits above a garage and I have a situation where the a 4" cast iron soil stack in a garage has been cut flush with the concrete floor. The stack was already broken at garage floor level and therefore needed to be replaced. Unfortunately, since it was broken at floor level there was no way to leave even an inch or two of it above the floor for a shielded rubber coupler. I am familiar with the rubber bushings that fit into a cast iron hub to make an easy transition to PVC, but I am unaware of anything available that is made to fit directly into a 4" cast iron pipe to make this transition.
My question is, is there is anything that exists for this situation to transition to 3" PVC or is the best practice to bust out enough concrete to use rubber coupler that can at least be partially buried? I don't have a photo of it at the moment, but basically just imagine a 4" cast iron pipe cut flush with a concrete floor.
I read about a similar situation on this forum where someone suggested the possibility of using a closet flange with the rubber gasket made to go into 4" pipe, but that sounds hacky and not something that will hold up over time. I think the person ended up digging it out anyway.
My question is, is there is anything that exists for this situation to transition to 3" PVC or is the best practice to bust out enough concrete to use rubber coupler that can at least be partially buried? I don't have a photo of it at the moment, but basically just imagine a 4" cast iron pipe cut flush with a concrete floor.
I read about a similar situation on this forum where someone suggested the possibility of using a closet flange with the rubber gasket made to go into 4" pipe, but that sounds hacky and not something that will hold up over time. I think the person ended up digging it out anyway.
