Installing Plumbing Shower Pans

Installing a plumbing shower pan for a ceramic tile shower is something that any good do it yourself can do in their home. All it requires is a little upfront knowledge. The most important portion of the project is properly installing the plumbing shower pan or shower pan membrane liner.

The Purpose of Shower Pans and Shower Pan Membranes

A plumbing shower pan is used to collect water that falls from the shower, and is used when a shower floor will not be tiled. The right shower pan will make a difference in whether your shower works properly or whether it causes mold problems.

Plumbing shower pans are fabricated out of fiberglass, acrylic, terrazzo and other materials. You should buy the best shower pan that you can afford, because you want it to last as long as possible. A discount shower pan may seem like a good idea at first, but flimsy pans will not last and will create leaks. Another benefit of purchasing a sturdy pan liner is that they are sometimes easier to install than their cheaper counterparts.

Plumbing shower pan membrane liners are installed when the floor will be tiled. Shower pan membranes will funnel any water that seeps through the floor or wall grout and into the shower drain. The shower pan membrane liner is made up of a flexible plastic material. It sits below a bed of mortar and is then covered by the tile. There are a few different types of shower pan membrane liners on the market. Each have their benefits, and you should do research before you purchase.

Installing Plumbing Shower Pan Membrane Liners

If you are installing a shower pan, the instructions should come with the shower pan itself. Installing a plumbing shower pan liner requires a few additional steps. Before installing the shower pan membrane, you need to pre-slope the floor. Pre-sloping the floor will ensure that the water flows toward the shower drain assembly.


To accomplish a pre-slope, apply a layer of mortar to the floor of the shower unit area. Trowel the mortar in such a way to create a gentle slope from the shower wall edges to the center of the shower, or where the drain resides.

Let the pre-slope mortar cure before installing the plumbing shower pan liner. Lay the flexible shower pan membrane liner on the shower floor. You will need to form and fold the material into the base of the shower area and secure it to the sides of the shower wall frame. Use staples and/or nails to secure the liner. Make sure to cut an opening in the membrane to allow the adjustable drain assembly to fit in.

After you install the plumbing shower pan membrane liner or shower pan, it is time to secure the walls in your shower. The cementitious ceramic tile backerboard needs to be placed over the shower wall frames and secured with nails. Once the backerboard is in place, you will apply a final coat of mortar to the shower pan membrane liner to secure the liner and prepare for the ceramic tiles.

Let the mortar cure, and then begin installing your ceramic tiles over the shower pan liner membrane and the backerboard. The tiles should sit for at least 24 hours before grout is applied. After you apply the grout, give the shower another day to cure, and then your new ceramic tile shower is ready to use.