When there is a tile or stone failure, a contributing factor is often the lack of properly installed movement joints. Just like concrete sidewalks and bridges, tile and stone need to have movement joints to control the anticipated movements within a structure.
Exterior decks and balconies, and interior showers and bathrooms, have historically been problematic areas for the installation of ceramic, glass, and stone tiles. Typically, problems are due to installer error, not using appropriate materials, or not providing clear enough specifications.
Whether it is a shower or an exterior deck or balcony, the waterproof membrane surface must be sloped to drain or away from the building. Shower pans or receptors are supposed to have a pre-sloped mortar bed installed over the base substrate before installing the waterproof membrane.