I know there are lots of PVC into cast iron discussion, but I have a problem I haven't seen answered. I live in a condo building built in 1840. We recently bought our condo and remodeled the bathroom. The sink, tub and toilet all join into one big PVC pipe before connecting to the cast iron building drain with a rubber no hub fitting.

Everything worked great, until the main drain plugged up and water backed up while showering. This left a lot of water in the PVC pipe above the no hub connection and the pressure pushed through the fitting, destroying a ceiling of my downstairs neighbor.

I agree the clog is in the building pipng, not my plumber's work. The plumber says the fitting simply was not designed to handle the pressure from water not flowing through. I also have found out this drain clogging problem has showed up intermittently over the years and I don't expect to convince the condo association to rip out the walls and replace the pipes without a LOT of discussion (e.g. Not any time soon).

We've snaked the drain and cleared the block, but the pipes are in rough shape and I expect this to come back. My question - Is there a connection the plumber could use for the PVC to cast iron connection instead of the no hub rubber fitting that would be able to hold the standing water above it without leaking? I need warning the drain is backing up before water starts coming through my very nice neighbor's ceiling.