Zinc is a naturally occurring metallic chemical element and the 24th most abundant element in the Earth's crust. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746. And once metallurgists perfected the process of smelting zinc into sheets, the natural metal became a popular building mate- rial, especially for roofs, in France, Germany and Belgium. Two hundred years later, some of those original roofs can still be seen on these historic buildings, especially throughout Paris. Today, environmentally conservative Ameri-
can architects and contractors who want to use more sustainable resources for their buildings are embracing the value of zinc for roofs and walls for several reasons. First, not only is zinc a naturally occurring
element, but compared to aluminum, copper and steel, it also requires a fraction of the energy to convert into usable materials. And architectural zinc is fully recyclable, from construction scrap to end of use, which lowers the energy use for manufac- turing even further. Zinc is also an extremely resilient building ma-
terial. A properly installed zinc roof can last as long as 100 years, virtually maintenance free. Compare
that to asphalt shingles that must be replaced every 25 to 30 years. Why does zinc have such a long life span?
Because it heals itself. Zinc develops a protective layer, called zinc hydroxyl-carbonate, that blocks moisture and chemicals from penetrating to the zinc beneath it. And if that protective layer is ever scratched, the hydroxyl-carbonate will reform over time. Conversely, when iron or metals containing iron come in contact with rain or salt, they form ferrous oxide, or rust, which corrodes the iron. According to the Northeast Recycling Council,
more than 10 million tons of asphalt shingles are dumped in landfi lls every year, where they leach toxic chemicals into the soil. Since zinc is fully re- cycled, it does not end up in landfi lls. Nor does zinc roofi ng or wall cladding leach harmful chemicals that affect the groundwater supply. In an article for TLC, a Discovery company,
titled, “Is Zinc the New Green Standard for Build- ing?,” Chris Conger points out the environmental hazards of other construction methods, including home building: “We hear a lot these days about going green inside the home. But what about the greenhouse gases produced from the construc- tion and maintenance of the buildings we reside
By Kim Weiss
in? Timber converted to wood paneling, noxious chemicals in paints, and the alteration of natural landscapes comprise only a few of the negative environmental impacts of new construction. For the green-conscious home hunters, zinc's proper- ties can ease this aspect of eco-guilt.” In addition, “the fl exibility, malleability, and ver-
satility of zinc, combined with its pleasing aspect, make it the material of choice for imaginative build- ing projects, from individual homes to commercial complexes, public buildings and private projects,” writes VMZINC on its website, www.vmzinc.com. VMZINC is the brand name for the architectural zinc manufactured by Umicore, a global materials technology group based in Brussels, Belgium.
Kim Weiss is the public relations coordinator for Umicore Building Products USA/VMZINC, Raleigh, N.C. An award-winning journalist and former magazine editor, she is also the owner and operator of Blueplate PR, a boutique public rela- tions fi rm headquartered in Raleigh, that special- izes in the building industry and primarily serves architectural and architecture-related clients. For more details on zinc as a natural building material, visit www.vmzinc.com.
Photography: Gilbertson Photography 36 METAL CONSTRUCTION NEWS July 2012 www.metalconst ruct ionnews.com