Well, I think my shower drain leak on one bath is fixed, now on to the second floor bath that was in worse condition when we moved in...a two piece fiberglass unit that we cut up and removed. (It was worn out, but was also leaking onto the ceiling below from one of the screw holes where the two parts were joined.) Anyway, after seeing the problems that were caused by that bit of engineering idiocy, and seeing it repeated in most of the units on the market, I settled on a 4 piece Vikrell unit (#7122). Sterling's installation instructions make no mention of setting it in mudas an option, but I understand the reasons why this can make for a better result. Can someone give, or give a link to, instructions for installing in mud? Questions that come to mind: What product to use? If product not specific to this application, how much water to mix with? Am I trying to cover just a portion of the floor (the oval that's the lowest part of the tub) or the whole opening, with a dam around the floor cutout? How thick? I've not opened the tub box yet, so I don't know what the bottom looks like, specifically how much contact area there is to provide support without mud. I've seen the home improvement shows where they just seem to throw a couple 5 lb pails of whatever thay mixed up under the center of the tub, but also know that what a pro can do casually in his sleep often requires a lot of thought, planning and research (learning!) for me. Any tips for this installation, especially for the specific Sterling unit, will be appreciated. TIA..... Ted.