How to Install a Fiber Glass Single Piece Shower

Remove the face plate around the shower knob, the shower head and the drain plate from the shower if you haven’t done so already. Take down any wall coverings already in place in the shower.

Measure up from the top of the shower pan where the fiberglass shower piece will sit to the bottom of the shower knob piping and note the measurement, and then measure up from the bottom to the top of the shower knob piping and not the measurement. Measure in from each side of the shower wall on which the shower knob is located to the edge of the shower knob piping and note the measurements.

Transfer the measurements to the front side of the fiberglass piece, measuring up from the bottom of the fiberglass single piece shower wall to mark the top and bottom of the shower knob. Make these measurements three separate times, roughly in the center of the wall and then two inches to either side of the first measurement. Use the same process to measure in from each side and mark the fiberglass where the sides of the knob should be.

Repeat the measurement process used for the shower knob for the showerhead, the drain and any other permanent fixtures in the shower stall. Once you have the edges of each fixture marked, use a compass to draw a perfect circle that connects the marks on the fiberglass for each fixture. Drill a hole through each of these circles and cut the circles out of the fiberglass single piece shower using a jigsaw with a fiberglass blade.

Press the single piece shower back into the shower stall, so that the bottom of the unit sits fully against the floor and the holes all line up with their appropriate fixtures. Secure the unit to the wall by the appropriate size screw, which generally comes with the fiberglass shower piece through the screw holes in the flanges on each edge of the shower.

Put the knob plate, drain plate and showerhead back in place in the shower to cover the cut holes in the fiberglass. Caulk around the edges of the shower to ensure a tight seal with the wall.