As with glazed porcelain and ceramic tiles, hairline cracks may appear overtime in cement tiles. It is rare, but it can happen. In the tiling industry, this is referred to as ‘crazing’. The occurrence of crazing can be a result of extreme fluctuations in temperature, movement of substrate or as a result of the adhesive used at the time of installation. Crazing can also occur over time naturally, it is not a defect and is not detrimental to the performance of the tile.