Building a Shower Pan

Slipsheet Installation

• The first step in building a shower pan is installing the slipsheet. The slipsheet provides a barrier between the shower pan's mortar bed and the wooden sub-floor. You can use a variety of materials, such as plastic garbage bags or a piece of roofing felt, for a slipsheet. The only requirement is that your slipsheet must be waterproof. In the event water seeps through the mortar bed, your slipsheet prevents the water from leaking through to the sub-floor.

Mortar Bed

• After installing the slipsheet, you must install a mortar bed. The mortar bed provides a solid base for your shower. While you can create traditional mortar with dry mortar mix and water, including a latex additive in the mortar mix, such as acrylic or ethylene vinyl acetate, increases the strength of your mortar and makes it more water-resistant. When smoothing the mortar with a trowel, shape the mortar bed into a slight slope toward the drain. Should any water leak through to the mortar bed or pan liner, the sloping shower pan directs it down the drain rather than out into the sub-floor.

Shower Pan Liner

• The shower pan liner sits on top of your mortar bed and serves as yet another leak-deterrent. Shower pan liners are generally composed of flexible plastic material, such as poly-vinyl chloride or chlorinated polyethylene, that you must fold into shape and install after the mortar bed dries. Alternatives to flexible plastic materials include lead sheeting and pre-formed, non-flexible liners.

Time Frame

• If you work steadily, you can complete your shower pan liner and begin installing shower tiles within a week. How long the shower pan you built will last, however, depends upon whether or not you completed each step in the process correctly and what types of materials you used. For example, if you use lead sheeting as a shower pan liner, your shower pan will last approximately 20 years before the lead sheeting oxidizes and is no longer effective at repelling water.