Clay and Concrete Tile Roofing Ideas from Cobalt Commercial Roofing
Clay tile has been used for hundeds of years in countries around the world. The raw material is readily available in many regions. It was used widely in the Middle Eastern countries and especially in China. Ancient Greek and Roman buildings were roofed with clay tile. Settlers of the United States from Europe particularly Spain, brought the tile roof with them. Clay tile roofs are still widely used around the world.
Today, clay tiles are carefully manufactured in a variety of shapes and colors. They are made from various clays, shale and other natural earthy materials and fired at high temperatures. Colors can be varied by mixing different types of clays. Clay tiles are also colored by spraying them with a thin creamy layer of clay, which, when fired, forms the color of the exposed surface. The appearance of the tile can be changed somewhat by flowing streams of natural gas into the kiln as the tiles are fired, producing a variegated surface appearance.
Another technique is to coat the surface with a glaze, which, when fired, produces a glassy surface. The glaze contains metallic pigments, enabling a wide range of brilliant colors to be available. The materials used to make clay tiles used in the US and Dallas must meet the specifications of the ASTM. While not popular with commercial roofing installs, this is a common look among high-end homes in Dallas, TX.
Concrete tiles are a more recent development. With the improvement in cements available and the use of additives, lightweight tiles with long-term durability now come in a range of colors. They are a mix of cementitious materials such as portland cement, hydraulic cement, sand, fly ash and more. These materials must also meet ASTM requirements.
The coloring of concrete tile can be produced by adding an iron-oxide pigment to the mix that produces color through the entire thickness of the tile. Another technique is to coat the exposed face with a slurry of thin cement mixed with an iron-oxide piment. This is sometimes used to add a brushed, random second color to the tile.