There are so many choices when building with metal.
More than 3 billion pounds of aluminum is used annually in U.S. construction, and much of that is in aluminum roof construction and wall systems of commercial buildings. Aluminum is highly receptive to today’s high-performance architectural coatings. A wide variety of factory-applied coatings and colors perform well and stay colorfast on aluminum roofs, which is critical for highly visible steep-slope roof applications. The coatings also help ensure virtually maintenance-free performance and long service life.
Long life and low maintenance are critically important qualities for exterior treatments of commercial buildings. Metal is emerging as the material of choice in many roof and wall applications, and copper is a popular choice among metal types. A primary reason for this is its permanency. Copper roofs can last decades, if not centuries. The oldest copper roof in the United States was installed on the Olde Christ Church in Philadelphia in 1742. In Europe, the copper cornice around the dome at the Pantheon in Rome lasted more than 1,800 years.
Steel is considered a universal building product because of its strength, versatility, durability, and economic value. Today, standing-seam metal roofs are used for countless structures, including shopping centers, schools, churches, and libraries. According to the American Iron and Steel Institute, steel roof construction is used in nearly half of all low-rise commercial, industrial, and institutional buildings erected in the past several years.
Terne is produced by coating metals such as carbon steel and stainless steel with a specially formulated alloy containing zinc and tin to dramatically increase corrosion resistance. When terne roofs were first used in colonial times, it contained roughly 80% lead and 20% tin. However, in the latter half of the 20th century, as lead was found to have potentially detrimental effects on health, the lead/tin alloy was replaced. In the mid-1990s, a new and superior zinc/tin alloy was produced that provides improved performance and aesthetics over the original—minus the health risks.
Building owners and architects are increasingly turning to zinc roof construction for its long, maintenance-free life and adaptability to various design styles ranging from traditional to modern. Zinc is a natural material that never fades and retains its look over its entire life span. It is also a noncorrosive, environmentally friendly product with a 100%-clear water runoff. Zinc's anticorrosion qualities have led its use extensively as a protective coating for steel and other metals.