Our range of Grey calibrated riven tiles come direct from Brazil, and are suitable for use on both floors and walls buying direct enables us to keep our prices as competitive as possible. All of our calibrated slate is machined on the bottom to give a consistent 10mm thickness across the tile, making them easy to lay for all abilities. These slates cut very clean, meaning that the riven surface of the tiles has a low cleft therefore durable and with natural anti-slip properties, but very comfortable underfoot. Suitable for use with underfloor heating