Shower Base Construction

• A shower base contains numerous layers. These layers together comprise everything that sits between your feet and the bathroom floor when you stand in a shower. Layers in a shower base include the shower floor, the shower pan and the pre-pan. The pan creates a waterproof layer that prevents moisture from permeating the pre-pan, or barrier between the shower floor and bathroom floor, and potentially damaging your home. Numerous materials go into the construction of a shower base, including tiles, lath, plastic sheeting such as polyvinyl chloride (PVC) or chlorinated polyethylene (CPE) and mortar.
  
  

Mortar

• All mortar contains the same basic ingredients: sand and a mixer. Mixers include cement, plaster and lime. Always use a “sand mix,” or cement-based mortar, for your shower base. When mixed with water or another liquid material, the sand and cement in a mortar mix form a clay-like substance that dries to create a hard bond. Builders, for instance, use mortar between bricks when building a wall. Mortar in a shower creates a level surface for the shower floor and helps bind the floor material to the shower base. Because all cement-based mortar contains the same basic ingredients, you can use any type of this mortar you want for a shower bed.
  
  

Mortar Additives

• Because all cement-based mortars contain the same basic ingredients, the quality of your mortar ultimately depends upon how you prepare it. You can mix mortar one of two ways to create the “mud,” or clay-like mortar used to build a shower bed: with water or with latex. Sources such as the book “The Complete Guide to Bathrooms” recommend using latex mortar additive. Mixing mortar with latex results in a material with twice the compression strength than mortar mixed with water. Compression strength describes a material’s resistance to breaking under pressure. Standing on a shower floor places constant pressure on the bed. Due to the relatively thin layer of mortar applied to a shower floor, the higher the compression strength, the better.
  
  

Choosing and Applying Mortar

• If your local hardware store sells multiple types of sand mix or other materials recommended for interior construction, always ask a hardware store employee about preferred brands for shower bed construction. You don’t want to build a shower bed only to find out after a few days or weeks that your mortar can’t handle the task. When applying mortar, do so in small quantities, slowly adding more as needed. If you add too much mortar at once, you may risk creating an uneven bed or a bed built higher than you drain.