: Hi -

: The P trap assembly in my basement bathroom sink fell off. In the past, someone connected the P trap and tailpiece to the drain pipe (metal, this is an older house) with some kind of rubber hose and hose clamps.

: The drain pipe barely extends past the wall, probably 3/4". OD looks to be 2".

: What is the proper way to connect the PVC P trap to the metal drain pipe?

: TIA

Reply:
If the drain stub out is gavlvanized, the proper connection would be with a no-hub (banded) coupling. It will fit over the galv. and PVC piping can be inserted, then the appropriate drain trap could be installed.
If it is copper stubbing out, a transition coupling can be installed. The rubber that you have now is what I consider a temporary repair, it's probably a Fernco coupling with two hose clamps, they're basically useless.
Good Luck. e-plumber