A tile reflective crack is a crack in a hard surface tile (i.e., ceramic tile, porcelain tile, stone tile, glass tile) which is caused by pressure transferred from a substrate crack to the surface tile. A substrate crack may be a small shrinkage crack which developed over time or an intentionally placed control concrete joint. Regardless, movement in the substrate may cause the hard surface tile to suffer a tile reflective crack near or directly above the substrate crack or joint.
An anti-fracture membrane should be applied to known cracks before tile is installed to mitigate against the future risk of reflective cracks. Control concrete joints, however, may be too wide for the successful use of a crack isolation membrane. In such cases, expansion joints or soft joints must be placed in the tile layer to permit anticipated movement.