Generally used on commercial, industrial or governmental facilities, the most commonly used types of metal system are aluminum, galvanized, galvalume and copper.  Metal systems can be installed in a pre-finished state, in which an optional point or coating can be factory-applied to reduce oxidation and improve aesthetic qualities.

A metal roofing system is generally classified as either an architectural or structural panel, based on its design and strength, and it can be further identified by the seam formation as follows:

• Standing Seam - This system is characterized by panel edges that rise vertically and can be capped or machine formed.  Standing seam panels incorporate a concealed clip that is mechanically fastened to the substrate.
• Batten Seam - Also known as "Board and Batten" panel systems, this class has a continuous vertical metal clip that is fastened to the substrate and clipped to the panel edges.  A metal batten cover is installed over the seam area.
• Flat Seam - This system is used on flat, low slope, very steep or unusually shaped roofs. 
• Bermuda - This system features horizontal joints rather than vertical ones, and it is installed from the bottom eave to the ridge.