Building an Accessible Shower Pan

No Curb

• The curb is the small wall or lip that usually runs across the opening of the shower to prevent water from running out. Removing this obstacle allows a wheelchair or walker user to enter the shower without a helper. However, taking away this wall allows water to flow back into the rest of the bathroom. Replacing the curb with a sunken trench drain catches a lot of the water attempting to run out of the shower without presenting an accessibility problem, according to the North Carolina State University College of Design.

Outside The Shower

• Adding extra water protection to the floor outside of the shower helps deal with any water that escapes an accessible shower pan design. Fine Homebuilding recommends adding a slightly sloped area of two feet around the opening of the shower that has a water-proof membrane below the flooring. Using the slope of a shower pan, which is 1/4th of an inch per foot, ensures proper flow. This redirects water back towards the shower and limits how wet the bathroom floor will become.

Add Depth

• The slope in a regular shower will not be sufficient to keep water moving when the curb is removed. A shower pan should be lowered about 3 inches and a new mortar bed with a 1/4th inch per foot slope should be built to make the shower drain better, says Tom Meehan for Fine Homebuilding. Run the top of the mortar bed to the height of the bathroom floor to prevent the creation of a small drop that makes the shower less accessible.

Advanced Drains

• Adding advanced drainage systems when rebuilding the shower pan also ensures the bathroom around the accessible shower stays dry. Linear drains are membranes that fit over the entire shower pan and under the tile finish to create a faster draining shower base, according to the ProLine Drain website. These membranes feature drain holes throughout the entire membrane and don't allow water to puddle up enough to flow out of the shower. If you're already rebuilding the mortar bed, installing a linear drain won't be much extra work.