Exteriors are made of steel sheet metal, which is covered by a thin layer of patina (rust) on exposure to normal atmospheric conditions, which protects the deeper layers of the material from corrosion. The sheets can be formed into exterior cassettes, and mounted to the wall by means of a steel substructure, in which thermal insulation of mineral wool with glass fibre tissue is usually installed.
Pros/cons: exceptional and unique appearance, and low price of materials. During the first months of use after installation, as a result of natural processes, rusty drips may form on elements situated under the exterior of the building.
Note: the installation of panels or cassettes of Corten requires considerable experience and knowledge. Unfortunately, Corten exteriors are most often installed by companies without the proper qualifications, who fail to use the necessary joints which provide ventilation between the individual panel edges, or stainless steel screws and other crucial elements. This results in a constant process of corrosion which leads to a shortening of the lifespan of the exterior.