Ceramic and porcelain tiles are as beautiful as they are functional, but they are very greedy when it comes to the space needed around them to absorb any movement. Many people don’t understand that when a surface such as a tile floor becomes warm or hot to the touch from direct sunlight or in-floor heating, they grow larger or expand. Allowing little or no room for the tile assembly to expand can cause the tile to pop up or “tent” in the middle of the floor. This situation occurs in both commercial as well as residential jobs, so none of them are exempt from this requirement.
This expansive growth must be accommodated with shock absorber-like areas known as expansion or movement accommodation joints. Since grout joints do not offer any movement absorbing qualities, these joints must be filled with a resilient material such as 100% silicone, urethane, of polysulfide. The Tile Council of North America (TCNA) Handbook, in section EJ171, clearly shows the shape, size, and location of these shock absorbers.