In reply to message posted by DUNBAR:
I agree with Dunbar. Get everything ready to go (drian connection, etc.) and lay the acrylic or fiberglass pan on a fairly stiff but still workable bed of mortar that has been carefully leveled and framed out on the subfloor, and you will wind up with a solid installation.
“Joint compound” may be easy to use right out of the can, but mortar really works best.