Tapering a Shower Base

Purpose

• The purpose of tapering a shower base is to force all water that reaches the shower floor to run toward a drain rather than collecting in the shower. This prevents water from pooling up where it can promote the growth of mold or mildew. Shower bases are typically made of a type of mortar known as mud. Applied in a claylike form, this mud hardens to serve as a base for the shower's liner and a floor of tile, vinyl or another material.

Layout

• In most cases, a shower base tapering slope is 1/4 of an inch, which means that the shower base close to the walls is 1/4 inch higher than the base at the lowest point, located directly around the drain. Shower drains are typically placed in or near the center of the shower stall, which prevents water from collecting in the corners or never reaching the drain. In other cases, drain location may be determined by the existing plumbing in your home and the bathroom's space limitations.

Traditional Process

• The traditional process for building a tapered shower base relies on using a piece of lumber to smooth out the mortar and a level to ensure that the base tapers evenly toward the shower drain. Marking the wall where the base should meet it, 1/4 inch above the level of the drain, provides a guide for building up mortar around the edges of the base. However, you'll need to use a flat piece of wood to ensure that the slope is even elsewhere with no flat areas.

Using a Kit

• Shower base kits are available that provide tools and materials for tapering a shower base. These kits generally contain tapered metal rods, which you can position around the central shower train hole with their wider ends closer to the shower walls. When you lay down the mortar base for your shower, the rods will serve as guides for the thickness throughout the surface. Rods remain part of the shower's base as the mortar hardens, allowing you to see if the mortar dries properly, or if it later settles into another position.