definition
strict definition
metal
Metal or metal-alloy materials used to form a building's exterior surface, commonly as thin sheets.
Metals are naturally formed malleable materials or blended combinations of natural metals. They are capable of forming strong sheets which are thin, long-lasting, and impermeable, making them useful as facade materials.
The metal forms the facade surface rather than necessarily the supporting framework. A thin metal covering can therefore lie over a frame of another material.
The material is separate from its surface arrangement and finish. Metal sheets can remain metal facade material when covered by paint or a thin protective coating.
