Exterior Products ReviewLongevity, Durability, and Recyclability Make Metal Roofing a Good Choice for Sustainable Building

There is a house in Omaha, Neb., that is unlike any other in the state—perhaps the country. Built under HUD's Partnership for Advancing Technology in Housing (PATH), this "Concept Home" is loaded with 60 of the best technologies and products home building has to offer and is seen as a model for the future of home construction. The roof the agency chose to use on the house is made from metal.

"Given the PATH Concept Home's concern with sustainability, efficiency, and flexibility in an affordable-home format, a metal roof was a sensible design choice," says Darlene F. Williams, HUD's assistant secretary of policy development and research, which supports PATH. "Along with its durability and fire resistance, the metal roof ensures the concept home will have beautiful, energy-efficient protection for generations to come."

Going the distance

Long the material of choice for agricultural outbuildings and barns, metal roofing has become the darling of the architectural community. Architects who favor metal—such as Kaplan Thompson Architects in Portland, Maine, and Peter L. Pfeiffer, principal of Austin, Texas-based Barley & Pfeiffer Architects—like it because it is attractive, lightweight, fire resistant, and durable.

According to the Metal Roofing Alliance in Belfair, Wash., a metal roof will last two to three times longer than a traditional asphalt roof. Once apt to corrode, especially in seaside applications, metal roofs now come with specialized finishes and coatings to handle salt spray.

"Steel metal roofing has a 'metallic coating' made of either zinc or a combination of zinc and aluminum ... [which] prevents rust from forming and is bonded to the steel at the factory," the association writes on its Web site. "Paint is then applied over the metallic coating to provide the long-lasting color homeowners desire."

It is one of these coatings that Follansbee Steel says allows its roofing to last longer than any other type of metal roof—and longer than asphalt. "The roofing features a zinc-tin alloy so it provides a good coat for the coast," says Lauren Ban, a public relations representative for Follansbee. "We have conducted a test where roofing withstood up to 5,100 hours in a salt-spray machine." HUD's Williams agrees, which is why the PATH house is clad in Follansbee's product.

Bill Zeigler, third-generation owner of Zeigler Contracting in New Ringgold, Pa., has witnessed metal roofing's longevity, having recently repainted a metal roof that his grandfather had put on. And since metal roofing weighs about a third as much as shingles, Zeigler says, it can go on over the shingles, avoiding the need for tearoff and thus saving space in landfills.

Green Roofs

For pros focused on sustainable design, metal roofing's recycled content and ability to be recycled also can be attractive. Manufacturer Taylor Metal Products, for instance, says on its Web site that its product can contain 90 percent recycled content, including 60 percent post-consumer content. Citing the NAHB, Taylor reports that composition roofing materials make up more than 5 percent (1.36 billion pounds) of the waste dumped in landfills each year. "Metal roofing is all recyclable if a home is torn down," says Tom Black, executive director of the Metal Roofing Alliance.