A relative newcomer to the U.S. market, zinc is enjoying remarkable growth as a building material. Discover how the metal enhances structures and gives buildings a unique look:

In recent years, zinc has caught the attention of North American architects and builders. They are finally discovering what Europeans have known since the 1700s—zinc makes an exceptional building material. In fact, the metal is so resilient that it can endure for 80 to 100 years as a roofing material and more than three centuries as a wall finish. Moreover, it requires little to no maintenance throughout its long life and accommodates a range of design styles from traditional to modern. For example, in traditional buildings, zinc is taking the place of lead for domes, copulas and flashing. And in contemporary and high-rise structures, it is used in modular panels equipped with rain screen technology.

Zinc can be easily shaped into a variety of structures, including shingles, tiles and flatlocks. And the fact that it can be formed into corrugated, trapezoidal shapes makes it appealing for industrial applications. The material is also suitable for a wide range of temperatures and conditions, from bitterly cold environments to blazingly hot locations and from high altitudes to extremely damp places. Indeed, while temperature may affect how a craftsman handles the metal, it has no bearing on the material’s longevity. And aside from being UV and temperature-resistant, zinc is also eco-friendly—it can be recycled and uses only a small percentage of its primary energy content.

The metal owes its durability to its natural tendency to form a patina of protective coating. It takes several years for this patina to develop, resulting from the combination of water and carbon dioxide from the air. Zinc carbonate or zinc chloride is formed. Builders must be careful, however, to prevent condensate from developing between the metal and the substrate. To make sure that zinc will live up to its potential for remarkable longevity, they must therefore follow the manufacturer’s detailing and installation requirements. In other words, they have to take care to give the metal some breathing room.

The look and feel of a zinc building will vary according to how it weathers outside conditions. In fact, even “pre-weathered” zinc will lose its gloss after a few months of exposure to the elements and attain a matte, reflective and blue-gray look. This means that each zinc structure will develop its own distinctive appearance over time, offering a variability that’s part of the unique appeal of the metal as a building material. Even zinc roofing material will weather differently from wall material, adding another architectural dimension. Moreover, combining zinc with small amounts of titanium and copper modifies material properties, such as expansion/contraction rates and color.

While its use as a building material is on the rise, zinc’s primary application is as a coating on iron and steel to prevent corrosion, which costs the U.S. over $200 billion a year. For example, the average automobile contains about 17 lbs. of zinc to fight rust. (Another 20 lbs. of zinc are found in die cast parts such as door handles and locks). In fact, zinc trails only aluminum and copper as the most widely used nonferrous metal in the U.S. Over one million metric tons of zinc are consumed a year. According to the U.S. Bureau of Mines, the average individual will utilize about 730 lbs. of the material throughout his or her life.

Aside from being used in architecture and as a coating, zinc is also claiming some high-tech applications. For example, it’s key to a new, zinc-air battery that can supply over 12 hours of run time to laptops on a single charge. Additionally, an alloy of zinc and copper is being employed in a water purification technology designed for industrial, residential, municipal and medical filtration systems. Also, the material is integral to a new, high-tech tape that’s allowing law enforcement officials worldwide to perform undercover work more safely and effectively.

Clearly, zinc is gaining prominence on several fronts, most notably as an architectural metal. From roofs to facades, on walls and on counters, zinc is an appealing choice for builders and architects because of its durability, flexibility and distinctive look.

Sources:

Understanding the Popularity of Zinc
Sheet Metal and Air Conditioning Contractors’ National Association
Architectural Metal, May 1, 2004
www.smacna.org/council/index.cfm?fuseaction=view_article&id=1657

Zinc Uses
American Zinc Association
www.zinc.org/zincuses.html