How to Install a Fiberglass Shower

Fiberglass shower enclosures are becoming more popular every year.

Manufacturers keep improving the appearance, the cost and the benefits of having a fiberglass enclosure as opposed to a traditional glass enclosure. One of the best benefits, is that fiberglass is easier to clean, and another is that fiberglass is more resistant to damage. Most of the newer models of shower enclosures are even designed to be so easy to install, that even a novice do-it-yourselfer will have no problems putting in their own shower enclosure.

Remove the old shower enclosure and fixtures carefully, and completely.

Place the new shower pan over the old one to make sure that the size is the same, and to ensure that there will be no leakage or drainage problems. If the fit is not compatible, you will need to get a different size pan.

Remove the previous drainpipes and pieces and clean up any residue. When that is done, put the shower pan in place and mark on the floor where the new drainpipes are going to be installed. Afterwards, remove the shower pan and then cut the hole and install the new drainpipes and P-trap and run the line to the main drain.

Attach your hot and cold fixtures where specified, and position the pipe fittings to be inline with the new shower stall. This may require cutting into the existing copper pipes and fixtures, sweat soldering them in the new spot, followed by the shower head installation.

Place the shower pan in position temporarily while the fixture knobs are installed to test the plumbing for leaks. This must be done before going any further. Insulation should be placed between the exposed wall studs in order to diminish the sound of water hitting the walls of the shower, and to prevent moisture and heat from escaping from the shower.

Mix the mortar exactly according to the manufacturer's directions. Follow the instructions that came with your new fiberglass shower enclosure to use the mortar to seal the seam where the shower pan and drain join together.

Measure and cut the holes for the shower fixtures and shower head in the enclosure. Attach the enclosure panels after applying panel adhesive around the edges of the panels and wall studs on the panel wall. Start at the base and attach them onto the wall moving upward. Thoroughly seal the seams between panels with silicon caulk.

Install green drywall or water-resistant cement board to all the areas above the panels. There should be a 1/8-inch gap left between the board and the stall walls, which should also be sealed with caulk. You can then paint the walls, or install tile to cover the areas.

Apply silicon caulk along the side and base tracks for the door, the seam between the drywall and the shower stall, and between the shower stall, the bathroom floors and the wall. Then you will be able to install the door itself, with no worry about future leaks.

Things You Will Need

  • Screw driver
  • Pliers
  • Small handsaw
  • Utility knife
  • Wrench
  • Shower pan
  • Pipes
  • Silicon caulk
  • Fixtures
  • Shower studs
  • Fixture knobs
  • Mortar mix
  • Door tracks
  • Door


  • Make sure that you have turned off the water to the bathtub or shower before you begin this project. Always follow the instructions that came with any equipment, tools, and product for home repair or remodeling.

About the Author

From her home in Wisconsin, Catherine has been writing content for a variety of Internet media since 2003. Her areas of writing experience range from baby care advice articles, to zoo animal research papers. Catherine is currently earning her Associates Degree in Communications from the University of Phoenix, and a Career Diploma in Freelance Writing from Penn Foster University.