Outdoor porcelain stoneware tiles must meet strict requirements and be resistant to frost, chemical attack, stains, wear and abrasion. Furthermore, they must guarantee color resistance to light, be non-absorbent, fireproof and resistant to external stresses, guarantee high mechanical and load resistance. Finally, they must be unalterable in climatic conditions, resist humidity and salt, be resistant to mold and moss, easy to clean, install and lay, easily removable and inspectable even when the floor is finished.