Tiles are man made materials, which are made from hardwearing materials such as clay, ceramic materials and sometimes they can even be made out of glass! This said, by far the most common material used to make roofing tiles is clay. Invariably tiles made this way out of clay have to be treated with a weather resistant glazing coat. People have been using tiles to build their roofs for hundreds of years and over this time people have designed many different shapes and sizes of tiles. Flat tiles, for example, are just about the most basic type of roof tile. They are more often than not flat and rectangular in shape which makes them ideal for layering on a roof. Flat roofing tiles are very, very common in applications and the methods used for creating these types of roofs have not changed a great deal since the 1970's! Other types of tiles are Roman tiles and single lap tiles. Roman tiles have a curve at one edge and another at the other edge; this allows them to interlock for additional strength when they are laid on a roof. Single lap tiles are shaped like the letter “s” and when they are laid they give a very distinct pattern.