The shower drain in my fiberglass shower is poking up and slightly off center, which caused a small leak. I had assistance with fixing it, but it gives very little clearance below for me to drywall the ceiling back up. I could shave the drywall down, but I also think the run from the trap to the main drain line is slightly off kilter which means eventually it may leak again. So I'm going to fix it proper so there is no sheering force at all.
My question is this – is there a minimum length the 2" drain from the shower must be before it hits the trap? I'm not touching anything after the trap except to connect my new drain/trap combo to it.
Because if there is no minimum (obviously you need a minimum to install the drain and couple the pieces together) I can definitely shave off like 1-1.5" of the drain line from the shower to the trap.