I have a project where the architect and designer have specified 12”x24” tile on a shower floor. I have told them that I cannot install this tile on a sloped shower floor without having lippage in my installation. Are there any standards concerning this?
There is information in the tile industry’s standards and guidelines about the size of tile to be specified for this situation. Mosaics are usually specified to reduce lippage on sloped floor installations. And mosaics are defined as any tile having a facial area less than 9 square inches. The TCNA Handbook for Ceramic, Glass and Stone Tile Installation, states “Lippage will be present when using tiles 6”x6” and larger over conical surfaces sloped to drain. Using smaller units in sloping areas will reduce lippage.” This verbiage originates in the tile industry standard for installations found in ANSI A108.02.
– NTCA Technical Team