A tile and a half is a common roofing terminology that refers to the length of a single roof tile, with an additional half of a tile added to the end. This is typically measured in inches or centimeters. For example, if a tile is 10 inches long, a tile and a half would be 15 inches long (10 inches for the tile and 5 inches for the additional half). This design allows for a more aesthetically pleasing and secure installation, as the extra half-tile at the end provides a more solid base for the next tile to be placed on, reducing the risk of gaps and ensuring a watertight seal.