Here's a tiling tip: The substrate is critical for optimal tile setting and tile performance. According to Chicago tile installation expert Century Tile, chipping and breakage can occur if the tile substrate is uneven. Plywood, concrete, and drywall are all used as tile substrates. The substrate must be leveled and cleaned before a waterproof coating or barrier is installed. One of our favorite contractors recommends using HardiBacker cement board as a tile substrate, because of its water-resistant properties. HardiBacker is a good choice for tiling kitchens and bathrooms.