Metal roof

Lead was one of the first and easiest metals to smelt and with a low melting point, it could be easily formed to be watertight.

[1] In the 3rd century BCE, copper roof shingles were installed atop the Lovamahapaya Temple in Sri Lanka.

The copper roof of St. Mary's Cathedral, Hildesheim, installed in 1280 CE, survived until its destruction during bombings in World War II.

[citation needed] In 1829, Henry Palmer, engineer of the London Dock Company, patented "indented or corrugated metallic sheets" which added additional stiffness to bending in one direction in the manner of a beam.

[7] After Palmer's patent expired in 1843, corrugated galvanized iron (CGI) became a world-wide favorite roofing material.

In the early 20th century, after being used for military purposes in the trenches and for Nissen or Quonset huts, CGI roofs were widely used but had low status.

[7] After architects such as Walter Gropius and Buckminster Fuller used the material, and with shiny and streamlined "desert modernist" designs such as Pierre Koenig's Stahl House (with an interior exposed metal roof, but not actual CGI), it recovered status.

The highly reflective coatings in the paint of metal roofing can lower utility bills by 40%.

[citation needed] Because of their longevity, most metal roofs are less expensive than asphalt shingles in the long term.

[11] It does not get as hot as asphalt, a common roofing material, and it reflects heat away from the building underneath in summertime.

Standing seam metal roofs come in sheets up to or sometimes more than 30 feet (9.1 m) long and widths of 12, 14, 16 or 18 inches (300, 360, 410 or 460 mm).

The fastener heads breaking off potentially is the down side to this method if installed improperly or from wear and tear from the fluctuating climate.

[17] Corrugated metal roofs are prefabricated sheets that are bent and wavy to make them more rigid.

Copper is used for roofing because it offers corrosion resistance, durability, long life, low maintenance, radio frequency shielding, lightning protection, and sustainability benefits.

[19] Today, copper is used in not only in roofing systems, but also for flashings and copings, rain gutters and downspouts, domes, spires, vaults, and various other architectural design elements.

[20] Several types of coatings are used on metal panels to prevent rust, provide waterproofing, or reflect heat.

Ceramic coatings can be applied on metal roof materials to add heat-reflective properties.

[21][22] Clear coatings preserve the natural color, warmth, and metallic tone of copper alloys.

Oils exclude moisture from copper roofs and flashings and simultaneously enhance their appearance by bringing out a rich luster and depth of color.