There are a number of issues that can cause your fiberglass shower floor to make an awful squeaking sound, but almost all of them are completely preventable with the proper attention and maintenance. Inspecting your floor and subfloor for damage and loose floorboards, choosing the correct flooring material, and making sure the floors are waterproofed appropriately is a good start. It is also important to install shower pans properly, preferably with thinset underneath. This article covers all the details for preventing that dreaded squeak.
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