Constructing a Shower Pan That Won't Leak

What You'll Need
Mortar mix
Waterproof membrane
Drain base
Concrete finishing trowel
Backer board
15 lb. roofing felt
Galvanized wire lath
Caulking and caulking gun
Plumbing tools

If you install your shower pan improperly, you could end up with a shower that is leaky. By following a few simple tips and installing a leak proof shower pan the first time, you will save yourself time and money in the long run.

Step 1 - Set the Subfloor

    You want to make sure that you have a solid subfloor in place. The most commonly thing used is backer board. A solid sub floor makes it easier to do the rest of the work.

    Step 2 - Rough Set the Drain

    This is the first step to ensure that you do not end up with a leaky or poorly drained shower pan. If you rough set the drain higher than the finished floor will be, the water won’t be able to drain properly and will most likely pool on your shower floor, possibly overflowing onto your bathroom floor. Because of this you want to make sure that the drain will be flush with the finished floor. Also make sure that you use a proper shower drain, since it has a secondary, lower drain to catch any water that may seep down.

    Step 3 - Slope the Shower Pan

    Making sure that your shower pan is sloping in towards your drain is essential to stop leaks and making sure water doesn’t pool in the shower pan and eventually spill out to your bathroom floor. You want your floor to slope at least ¼-inch per foot. Once you have calculated the slope you want, nail ¾ X ¾ inch float strips on the perimeter of the shower pan for guidance. Next, cover the floor with roofing felt and then a layer of wire lath, stapled flat.

    Step 4 - Apply a Layer of Mortar

    Because you are applying a thin layer, mix the mortar with a latex additive that will add strength to the mix, rather than water. After mixing the mortar, apply a layer to the shower pan. Allow to dry overnight.

    Step 5 - Install the Waterproof Membrane

    Measure and cut the membrane to fit the shower pan, making sure that you allow for 8 or 9 extra inches so that it can go part way up the walls. Place the membrane in the shower pan, folding down the corners. Cut out the hole for the drain. Once it’s in place, attach the membrane to the wall at the top using staples. Between the layers of your corner folds apply sealant in order to secure the membrane tightly against the wall blocking.

    Step 6 - Apply a Second Layer of Mortar

    Apply the second layer of mortar, once again sloping towards the drain. Leave it to dry.

    Step 7 - Tile the Shower Pan

    Apply thinset and then tile your shower pan. Once you have applied the tiles, then grout.

    Step 8 - Apply Final Sealant

    The final step to making your shower pan leak proof is applying the sealant. Use a grout sealer on the tile floor and make sure to regularly reapply to keep your shower pan leak proof. Make sure to maintain the caulk seal along the wall and floor as well.