The difficulty of installing a shower floor depends on the type of floor. Installing a preformed shower floor is much easier than installing a tile floor. If there is an existing shower pan that is not tile-ready, the installer must create a slope to drain the water.
A preformed shower pan is the easiest way to install the floor. The flat shower pan is the less expensive model and works well if you have no plans of installing tile or stone. If you plan on adding another layer to the floor, the more expensive sloping pan is the better choice. For showers that do not fit a standard shower size, one option is installing a rubber membrane under the tile, which is more difficult than installing the pan.