Light Guage / Low Cost Building System
Cold formed steel is shaped by guiding thin sheets of steel through a series of rollers, each roller changing the shape very slightly, with the net result of converting a flat sheet of steel into a C or S-shaped section.
The steel used here is coated with zinc (called galvanized) or a mixture of zinc and aluminium (called zincalume or galvalume by some) to protect it from corrosion. The thicknesses of steel used here range from about 1 to 3mm for structural sections, and 1 to 2mm for non-structural sections. The members are sized to roughly correspond to wood members: 2″x4″ and 2″x6″ are common sizes, manufacturers to produce light-weight but high tensile steel sheets.