Unlike traditional tile showers, one-piece shower units are prefabricated fiberglass or acrylic enclosures. These units include walls, a base, and possibly a door.
Pros and Cons
Prefabricated shower units are cheaper to install than tile in terms of both labor and materials costs. However, they lack the aesthetic features of tile showers. Prefab showers are only minimally customizable. Also, tile showers can be built to any size in any location, whereas prefab showers are often limited by the size of the entrance door to your building or bathroom.
Measure the shower cavity to select an appropriately sized unit. Lay out the location of the plumbing fixtures on the floor and walls by making a cardboard template. Use the template to mark on the shower walls. Drill ¼ inch holes from the unfinished side, and then widen them from the finished side. Slide the prefab shower into place to make sure it fits. Remove the shower and apply mortar, plaster, or adhesive to the floor of the cavity. Set the unit in the cavity and fasten its back and side flanges to the wall studs with nails or sheet metal screws. Finally, caulk around the edges of the shower and the plumbing fixtures.