Liners for shower pans are available in a variety of designs and colors, but if you want something that isn't on the market, you can build a shower pan liner yourself. A custom liner will still have to keep the floor beneath your shower completely dry, so you will have to use material that will adapt itself to the shower pan. Follow these steps to build a custom pan liner for your shower.
Step 1 - Measure Your Shower Pan
In order to build a liner which keeps your subfloor and other rooms below the shower dry, you will need to carefully measure the length, width, and depth of the shower pan. The liner must be built to reflect all of these measurements. You will also need to add extra cloth in order to fold the liner corners. Before you can install the liner, the area under it should be sloped so that water will flow down into the drain assembly parts. Make such allowances when you are measuring the area.
Step 2 - Build the Liner
Once you have the measurements for your shower pan and the floor beneath it, you can use them to cut material for your liner. Cut the liner so that there is a slight excess. That way, you will be able to fold the corners to fit. It is a good idea to sew 2 pieces of material together to make a stronger and more durable liner. Sewing the edges will protect the liner, although you can manage with just a single sheet.
Step 3 - Lay the Material
Cut the material to your planned proportions and lay it at the base of your concrete floor. Make a hole in the appropriate position for the drain assembly, then install it, adding caulking around the the cut. You can fold the excess liner around the curb so that the center is taut towards the drain parts. Fold the corners of your liner so that the loose ends are under the main body of the liner and nail it into place, Then caulk the edges of the liner.
Step 4 - Finishing
Once you have caulked the edges of your liner, leave to dry for 48 hours before adding the shower pan. Place the pan so that the sides are contained within the liner. Caulk the base of the pan in order to ensure that water does not leak.