I'm installing a 36" x 36" PVC shower pan in a 2nd floor bath. I have a two piece shower drain where the bottom piece is glued to the 2" PVC waste line. It appears that I'm to glue the bottom piece flush with the subfloor, lay in the pan, and screw down the top of the drain (w/ rubber gasket). My concern is applying the necessary torque on the top to ensure a proper seal. Isn't that alot to ask of a glued connection? Note: I do not have access from below to hold the bottom nut in place. Or is this the wrong fitting for a "above-only" installation?

The shower pan did come with a slip-over fitting but it did not present a tight fit and I wasn't confident in it's ability to seal. Thanks for your help. Bill

This application requires a different type of shower drain -- What you need is called a 'No-Caulk' shower drain.

I have learned recently from 2 different plumbers in here about a drain that does that job and the shower drain is well built. I also have found a drain at Lowe's that is not as good as their drain but works anyway. It works like you said. Mount it by gluing on the pipe then screw the top piece down from above. Don't forget to use putty.