I decided not to hire the hotmoppers since they couldn't prefloat our floor (drain is not directly in center of shower space). Since I had to hire someone else to prefloat the floors, I decided to just have that person do the entire shower floor up to tiling. That meant installing a vinyl liner and then putting a mortar bed on top of that as well as floating the wall to match the cement board. Next time, I can avoid all this hassle by installing a premade vinyl pan, but I really do like the look of a tiled shower floor :-)
Here's the process:
First, the floor is presloped towards the drain by building a thin mortar bed; code requires 1/4" drop for every 12" run. The vinyl liner will sit on top of this. This insures water that gets past the tile and mortar will hit the vinyl liner and flow towards the drain, rather than just standing and growing mold and mildew.
Next comes the vinyl liner - cut to size and folded:
then placed on top of the preslope:
A two part drain cap is placed over the vinyl. The cap has weep holes which allows water in the liner pan to drain out. A test plug is dropped into the drain so the pan can be filled with water for inspection.
The inspector will want to see the liner hold water as well as seeing the water drain thru the weep holes.
After passing the shower inspection, the mud guy came back and finished the job with a 2nd thicker bed of mortar:
Now the shower's ready for tiling!