A handicap shower stall has a number of special requirements which should be fulfilled before a handicapped person uses the shower. Fitting a shower pan for a handicap shower stall is one element that requires careful thought. The pan will often need to have no threshold, so that wheelchair users can easily access the stall. It also needs to be larger than a standard shower pan, as it needs to be able to accommodate a wheelchair.
Most shower pan installers use a waterproof membrane across the entire shower floor, turning the shower room into a wet room. This can be pricey, and sometimes it's just as efficient to do it yourself. The advantage of laying out the shower pan like this is that the shower can be gently sloped towards the entrance, meaning that a threshold is not needed.
Step 1: Plan out the Handicap Shower Stall
You need to have the shower head and attachments as far from the entrance as you can. Start by calculating the slope away from the shower. There should be a drop of around 1/4 inch for every foot in length. You can stop the slope around a foot away from where the water will hit.
Step 2: Beginning the Pan
Begin by putting down roofing felt or plastic, and cover it with the wire mesh. Fix these in position with nails, or if possible screw the mesh down, one screw for every 6 or so inches.
Step 3: Mix the Mortar
Mix up some mortar: one part cement to three or four parts sand. Add enough water to form a tacky ball that does not fall apart. Place the mortar around the mesh and plastic to create the slope. There should be a slight bump at the entrance to ensure that water does not come out of the handicap shower stall and into the rest of the house. You should also place the drain in the concrete, and leave the whole lot to set overnight.
Step 4: Place Backerboard
Once the concrete is dry, place the backerboard over the top, covering the concrete in a thin layer. You should go over the walls to ensure that any splashback is properly handled.
Step 5: Add the Membrane
Add the membrane to the floor, using waterproofing membrane folded in half to seal the floor and walls. Make sure that the entire area is waterproof, and seal with a layer of thinset.
After 24 hours, check that the handicap shower stall has been waterproofed, by partially filling the shower with water, and leaving overnight. You should have no leaks or loss of water, and the shower should not spill out into the hall or other living area. If you are planning to add a layer of ceramic to your handicap shower stall, cover the area with thinset, and allow to dry before placing any tiles.