Get a professional plumber to rough in the shower drain before starting the concrete installation.
How to make a shower floor.
The top of the drain should be 2 inches above floor height and you want to mark the walls and curb to a height 2 3 4 inches above the floor as a guide to the amount of mud you need to maintain a 3 4 inch slope.
The easiest way to make your shower floor less slippery is to add traction by installing an anti slip shower mat.
Lay a large sheet of tar paper on the entire floor of your shower pan and smooth it out as flat as possible.
Pour mud into the shower pan mixing it with a trowel as you go to get rid of air bubbles.
They re cheap easy to install and immediately add texture to your floor which significantly reduces your chances of slipping.
Also make sure your floor is pre sloped before installing the rubber liner in the following steps to prevent.