Recessed niches inside the shower are very handy for placing shampoo, soap and other bathing products. Usually such niches are noted by their absence when a person tries to find a home for his products and is left with the option of hanging a wire rack over a faucet head because the shower doesn't have a niche. Installing a niche in a shower has become easier with new products designed to create watertight shelves that can be covered in the tile of your choice.
Select a pre-manufactured recessed shower wall niche from a manufacturer like Aquafit USA. These pre-made products are designed in several sizes so that they can be installed easily between studs. These niche units are shaped like a box with a flange on top. The backside of the box recesses into the shower wall.
Determine the location of your studs. You should be able to see screw heads through the concrete board. Position your pre-made recessed niche box against the wall. Stand inside the shower as if you were using the shower in order to determine a good height. Often this is around 5 feet from the floor and centred.
Level the niche box between the studs and trace around the backside of the box on the concrete board. Measure a half-inch around the outside of the traced lines and draw new cut lines. Your new line should not cut into a wall stud. Cut the board with a hooked carbide-tipped knife.
Apply a continuous bead of adhesive caulk to the back of the flange and secure the recessed niche into the wall cavity using the fasteners provided by the manufacturer.
Feather the edge between the flange and the concrete backer board by applying thinset mortar to the area starting with a 6-inch putty knife and working outward to finish with a 10-inch putty knife. Allow the thinset to dry over night before tiling.
Tile over and into the recessed niche. This niche product has a built-in slope to shed water back into the shower area. Additional shelves can also be installed inside the niche at this time. Finish adding the tile.
The flange on this type of recessed niche product can be recessed into the concrete backer board if the contractor has the tools necessary to grind down the concrete board around the niche opening. This will produce an even smoother finish.