Building a shower pan
I plan on installing a mortar bed shower pan with a liner in it. The one thing I'm curious about is the finish mortar bed. After pre-sloping a mortar bed beneath the liner, do I additionally need to slope the finish bed or can I put in a 1 1/4 inch layer following the slope of the previous bed? It seems to me as long as the finish bed has a 1/4" per foot slope that should do.
The setting bed should be the same thickness all over; in other words, parallel to the sloped liner. If you haven't checked it out, check out www.johnbridge.com for tiling help. The areas most people mess up is locking the bottom layer of cbu and vapor barriers over the liner plus dam corners and properly making the curb. All of those items are covered over at that site, and lots of tiling pros for help.
The shower floor has to pitch to the drain, regardless of whether it has the same slope as the subfloor or not. I am not sure if I understand the reason for the question, however, because you would not install the tile on a level plane.