I'm trying to install a new bath on a 2nd story where there wasn't overflow piping before even though there was a bath. It's all ABS 1 1/2" piping.
However, there is a support beam / joist in the way as seen here:
My solution is to try to go right over the joist rather than drill a hole through it by cutting out the drain that is there, using a san tee with the drain on top, and a dirty arm over the beam leading to the overflow fixture, leaving the p-trap where it is. That way the drain would continue to function as it has been, and if there is an overflow, it would just dump into the existing drain.
However, I can't seem to find an ABS tub drain rough in like the one picture that goes straight down. Anyone know what exactly it would be called? The only ones I can find are the 90 degree angle pieces for the whole drain/overflow kits that they sell at places like Home Depot. Would it be possible to find such a rough in for the drain in male rather than female form? That would make it a million times easier to attach it to the san tee.