Sometimes, severe flexing can stress the drain fittings and may cause a leak around the shower drain. When the pan is level, stable and securely mounted, itâs time to make all components water-tight. You could put plastic sheeting on the floor and then set the pan in mortar or plaster on top of the plastic. This AcrylX applied acrylic shower pan comes in a neutral white that goes with every bathroom color scheme. Most modern shower pans are either acrylic or fiberglass for ease of installation, but keep in mind that some shower pans may have to be special ordered if theyâre not a standard model or size. It's necessary to install basic support at the subfloor level. Frame the shower bench such that the 2x4s are 12″ on-center and about 20″ to 26″ high. Seal penetrations and abutments to dissimilar materials. It may be possible to access the bottom of the shower pan from a room below the shower. If the present shower pan was installed with mortar, you most likely will need to purchase a new shower pan since the current one may become damaged when you remove it. All plumbing fixtures come in a range of quality standards and shower pans are no different. This project involves some advanced plumbing knowledge and skills. Because you can install sheet vinyl over existing vinyl, it offers the option of changing design without breaking the bank. A little movement (about a half-inch or so in each direction) of the pipe is fine, and will help when lining up the drain components. Prefabricated shower pans come in one of two types: those that are installed in a bed of mortar spread over the floor and mortar-less pans that are designed to rest flat on the floor. If your shower base and drain fitting have been correctly installed, minor flexing will likely cause no problem at all. Install backerboard with ends and edges closely abutted but not forced together. Reply. This is dependent on whether or not you've prepped for it: walls, floors, etc. The fiberglass shower pan goes on the subfloor. Few prefabricated shower pans will feel as rock-solid as a tiled shower base. When replacing a shower pan, some shower pan manufacturers call for the shower pan to sit directly in an adhesive or into small mounds of mortar. See Step 1 for more information. Shower pans have weight limits. In severe cases—especially if the flexing has caused the shower pan itself to crack—the only solution is to remove the base to make the necessary repairs. Step 3 - Attach Drain Assembly to Shower Base. Shower bases, or pans, made of acrylic, ABS, or fiberglass make life easier in so many ways for homeowners and for installers. Wipe up any accidental drips of caulk from the pan before they dry. Wood floors first need to be able to withstand the weight of a custom walk-in shower. But I discovered that instead of wood studs, I have metal studs and can't drill into them. Ramset 40088 Heavy Duty Powder Actuated Hammer, 0.22 lb, 18-1/2 in L, Steel, Black Available For Local Delivery This ensures the water will drain evenly from your shower. Shim it if necessary before nailing it to the subfloor. Be especially careful to avoid using chemicals known to deteriorate acrylic, ABS, polystyrene, fiberglass, or plastic. Be sure to follow the instructions on the container for drying time. Do NOT use mortar or cement, as these will cure too quickly for most do-it-yourselfers. To learn how to measure for a new shower pan, read on! All the flooring and subfloor has been removed, and I'm at the point where I am getting ready to replace some joists and sister one.