If your experience with residential metal roofing is limited to a standing-seam job on a rural vacation home or a copper-topped eyebrow dormer on a redone Colonial, it's time to update your spec books.

In an attempt to capture a larger share of the residential market, the metal roofing industry has expanded its product offerings far beyond the conventional vertical interlocking (standing seam) steel or aluminum panels and individual shingles and tiles you're probably familiar with. Today, there are metallurgic versions of dimensional asphalt shingles, wood shakes, Mission-style tile, and simulated slate. And those new looks are being fabricated into panels (or modules) that cover more area than a three-tab shingle and fasten directly to the roof deck.

"We're creating metal roofing for the masses," says T.J. Brown, general manager of Gerard Roofing USA, in Brea, Calif., who hopes the company's new Guardian shingle, a stone-coated panel, will help the company snag a larger share of the 170 million squares of roofing installed annually. "The biggest obstacle [to boosting market share] is the lack of awareness outside the context of standing seam."

Closing the gap

The industry's challenge is compounded by the perception that metal is simply too expensive for mainstream housing--especially if home builders are involved in specifying the roofing finish. "Builders are reluctant to put any extra money into the roof," says Brown. "They don't think they'll recoup the cost."

Until recently, the price barrier for metal roofing has been twofold: Not only is the initial cost of the material itself prohibitive, but its installation is expensive, too. "The biggest influence on overall cost is the geometry of the roof," says Tom Black, executive director of the Metal Roofing Alliance, in Seattle. Traditional metal roofing, whether long panels or individual shingles, is harder to cut and apply on site than other finishes, he says, requiring special bending tools and fasteners, particularly if the roof is steep or complex in its design.

In their search for ways to make their products more attractive in terms of both cost and aesthetics, metal roofing manufacturers looked at trends in asphalt comp finishes. "We saw a housing market that wanted more durable and expensive-looking roofs," says Brown, referring to the increase in premium-grade laminate shingles. In response, Gerard and other companies developed modular roofing panels embossed and textured with stone coatings to replicate that look. "It's an opportunity for us to develop a product on our lower end that's comparable in its dimensional profile to high-end laminate shingles," Brown says.

The new-look metal roofing also addresses installation costs. Gone are the cumbersome rows of battens; rather, the modules are applied to the deck from eave to ridge with common roofing fasteners, just like a three-tab shingle--though the modules do interlock on all sides to help seal the roof and prevent tear-offs in high winds. While the simulated shakes and shingles make metal roofing appropriate for a much wider variety of home styles, "the real benefit of modular panels is quick installation," Black says.

Yet another advantage of the new panels is that, unlike conventional standing-seam products, they do not involve special-order requirements. Instead, they're available through standard distribution channels and contractors.

Educating architects

In addition to training installers, manufacturers of modular metal roofing are conducting seminars for architects, with many classes qualifying for continuing education (or CES) credits. "Architects understand the concepts of life-cycle costs and low maintenance associated with metal roofing," says Nancy Carl, with ATAS International, in San Diego and Allentown, Pa. "They're interested in metal's advantages over other roofing products."

The primary advantage of a metal roof, especially for reroofing, is its light weight. At less than 1.5 pounds per square (compared with twice that or more for high-grade asphalt comp), metal can often be installed over an existing roof finish, eliminating tear-off chores and cost. And, unlike much heavier concrete and fiber-cement finishes, metal does not require a beefed-up roof structure for support.

A common knock on metal, however, is its potential for corrosion and its poor impact resistance. To address these issues, makers have invested heavily in new coatings. Although polyester resins remain popular (because of low cost), more advanced silicone additives (or SMP coatings) and fluoropolymers (trade names Hylar 5000 and Kylar 500) better mitigate thermal, chemical, and UV intrusion, and thus minimize problems with cracking, chalking, and fading. Trade groups also recommend a G-90 zinc coating on both the top and underside of the metal for corrosion protection. Stone-coated varieties create a weather and wear barrier for their metal substrates, and new insulation and underlayment products lessen noise as well as thermal transfer and expansion.

In addition, factory-coated aluminum panels are recommended for coastal or other extreme conditions to limit rust potential, while the stone-coated and dimensional profiles (as opposed to the long, flat exposures of a standing-seam panel) hide or even diminish damage from hail. In fact, the Texas Department of Insurance classifies metal roofing as resistant to the state's notorious hail storms, resulting in 35 percent reductions in premiums related to roof damage coverage in homeowner insurance policies.

Black concedes that it may take a while to overcome the popular view of metal roofing as a corrugated barn cover or a snow shed on a ski chalet. "There's a limited sense of what metal roofs look like, especially for residential," he says. But with these new modular products and their varied looks, those perceptions may well start to change.


Resources 

Metal Roofing Alliance, Seattle
888.638.2573
www.metalroof.org
The MRA is a coalition of metal-roofing manufacturers, paint suppliers and coaters, dealers, metal producers, and related companies and associations focused on the promotion of residential metal roofing.

Metal Construction Association, Chicago
800.797.8335
www.mca1.org
The MCA is a trade association concerned with all use of metal in construction. Offers "Guide Specifications for Residential Metal Roofing" (cost: $10), among other publications and resources.