What is the process of making concrete tile? Concrete tile is the process of bringing all the raw materials together and actually mixing it. These materials are sized aggregate, cement, water and pigment.
Concrete roofing expert Andy Dolan of Concrete Columbia Concrete Products, Ltd. compares the process of making concrete roofing tile to baking a cake. "The process involves bringing all the raw materials together and mixing them. These materials are sized aggregate, cement or lime, water, and color pigment. Typically the aggregate that is used is a blended aggregate. We liken it with putting golf balls into a bucket. If you just put golf balls into a bucket, it would have voids and holes in it. To prevent that, you put in marbles and tennis balls to fill up those voids. The consistency of the mixture can't be too wet and it can't be too dry. Once it has been produced it's the same consistency as snow. You should be able to pick it up and squeeze it hard and it should stay foamed. That's a perfect mix."
Once the perfect mixture has been produced, it is delivered to an extruder or concrete roofing machine where it is squeezed out onto an individual mold and then rolled out under very high pressure. It comes out looking like spaghetti because each mold is backed up head to head. The tiles are then cut at a very high speed. In a factory the tiles are usually produced at the rate of two tiles per second, and there are thousands of molds on the line at any one time. Once the tiles have been formed they go into a curing chamber for several hours. At the end of this process the tiles are very hard.
Variations in concrete roofing tiles are made by changing the mold patterns or color pigments. Dolan says that his company does not offer custom tiles because, "It's a very expensive proposition to undertake, and we produce the tiles that we think are going to be aesthetically pleasing to the market. We offer tiles in a limited variety of colors and profiles. Each profile change is an investment in mold change, and to get the return on your investment, you have to be able to sell a lot of them." He says that there are opportunities for custom tile designs, especially if the project or order is very large, but that it is rare and manufactures tend not to offer custom options. He notes that California is one area where a large variety of colors and designs are readily available. Depending on the region and the producers, the choices will vary. In Florida, for example, light colored tiles such as pink and white are the most popular. In the western states earth tones such as orange, terra cotta, and browns are more predominate. In the eastern states blues and grays are more likely to be seen. Some manufacturers even offer textured or distressed surfaces to achieve a special look. Concrete roofing tiles can be designed to replicate Spanish, Mission, Mediterranean, English Tudor, Georgian, and Cape Cod styles. They are very versatile and offer an economical and lighter weight alternative to clay and slate roofing materials.
