Waterproofing the walls
It might be good to review the importance of waterproofing. Tiles and grout are not waterproof. Therefore, in order to avoid mold and mildew issues waterproofing must be performed on the walls before tiling. While there are several methods of waterproofing, we feel the simplest and most effective is the Schluter shower system. Please review the below video or take a moment to watch so that you understand the importance of waterproofing the entire shower.
Kerdi Fabric / Membrane over existing walls
Kerdi Board In place of traditional walls
Simple Tile Shower 