There was a time when a prefabricated shower unit was only considered for new construction or remodeling as the units were designed and constructed in one large piece. Installing a shower pan and separate side panels of multi-piece units require more skills than a one piece unit. While there are varying opinions on which unit is more difficult to install, you may be better off hiring a professional to install a multi-piece shower unit. While installing a one piece unit is not an easy project, with the right planning and a little care, installing a prefabricated shower unit can be simpler than you may think.
Step 1 – Measure
This may feel like the biggest part of the job. Take your time and measure accurately and the installation will go quickly. Measure the space you have available to install the unit, if this is new construction it is advisable to have a professional plumber set up all your new plumbing requirements. Measure the space you have available to get the unit into the room. Don’t forget about the front door or a stairwell if that is applicable. You will want to make a cardboard template for the plumbing measurements. Make two separate templates - one for the drain area and one for the faucet area.
Step 2 - Install Wall-Board
The walls behind the shower unit need to be protected with moisture resistant wall-board. Finish installation of the wall-board with a coat of latex primer.
Step 3 – Make the Plumbing Holes
With the cardboard templates and measurements you have created, mark the unfinished side of the shower pan for the drain hole. With the template in place drill a ¼ inch hole in the center of the template through the floor of the shower. On the finished side of the shower pan line up the hole from the template and the hole in the unit and mark the finished side of the unit. Use the jigsaw to cut out the hole. Repeat this process for the faucet holes using the faucet template.
Step 4 – Level the Unit
Place the unit into the area it is to be installed. Double check that all the holes line up accurately, place a level on the unit and verify it is able to sit level.
Step 5 – Install the Unit
Following all manufacturer’s instructions apply plaster or adhesive to the well area where the shower will sit. Do not add too much adhesive. Replace the unit into its location and check the level again. Most units will have flanges on the backside. If nails are not provided with the shower unit, use galvanized nails to attach the flanges to the studs.
Step 6 – Attach Hardware
Caulk around the lip of the drain before installing the catch screen. Tighten the faucets and caulk around the fixtures.