A tile shower pan built the traditional way consists of several layers, but it's mostly mortar.
It's sloped floor too, because the water must drain toward the drain.
Getting the mortar sloped takes some skill, but it's actually a fairly simple process.
The proper slope for the floor is about 1/4 inch per foot.
That's enough slope to keep the water moving and not pooling.
Even the top of the curb should get about that same slope to keep the water in the shower instead of on the bathroom floor.
Now the floor mortar is called deck mud.
It's a special blend of just three ingredients.
Those are portland cement, sand and water.
Nothing else.
The dry ingredients are completely mixed dry, then water is added.
It's added slowly as mixing continues so you don't get too much water.
The final mixture should just stick together.
Soupy mixes will work for brick laying, but not for shower floors.
The deck mud is put in place with flat trowels and then is raked into place with short wood pieces.
It's continually scraped and rubbed into place until it's smooth and sloped properly.
The thing is you only have about 30 to 45 minutes to get it in place.
Then it starts to harden on you.
Tile shower pans are built with a simple three part masonry mix that's called deck mud.
No additives are required.
It's just a mix of portland cement, sand and water.
It's just scooped in place with a flat trowel, then scraped and rubbed into place with that same trowel and wood pieces.
Get the right slope on the mortar and finishing the floor becomes much easier.