The Rise of Metal Roofing
Long-lasting, lightweight, and resistant to hail and fire, metal makes an ideal roof.
Synopsis: Metal roofing is growing more popular due to a widening range of styles available and longer service life. Contributing writer Scott Gibson delves into all the different options for metal roofing, from materials to installation details. The article includes explanations of rating standards for metal roofing, as well as descriptions and pricing for a variety of roofing products, from modular panels made to look like shakes, shingles, and tile to classic standing-seam or through-fastened panels.
Metal roofing has a long history in the U.S., but until 20 years ago it was a bit player in residential construction, with just a 3.6% share of the reroofing market. That number has roughly quadrupled since then, according to an industry trade group.
What happened? Metal roofing is now available in a range of styles—from standing seam to a variety of stamped metal shingles that look like slate, clay tile, and even asphalt. Paint and stone coatings are more sophisticated and durable, giving metal roofing a long service life while appealing to homeowners with a variety of aesthetic preferences.
The industry is also working harder to win over consumers who once thought that metal roofing was too hot, too heavy, noisy, or prone to rust, says Dick Bus, president of ATAS International and head of the Metal Roofing Alliance. “Those myths are gone, and people want to reroof with something that has some permanence to it,” he said. Metal roofing may never catch up to asphalt in the residential arena simply because of sticker shock. A standing-seam or metal-tile roof can be two or three times the initial cost of asphalt. But its longevity, recyclability, high fire resistance, and low maintenance has increased its acceptance.
Select a base metal
Steel and aluminum are the two most common and least expensive metals used for residential roofing. “On about 80% of all homes, either metal will work just fine,” says Todd Miller, president of Isaiah Industries, a manufacturer of a wide range of metal roofing products. “On the other 20%, it tends to be driven by climate in that area.”
Steel’s weakness is its potential for rust. One way to prevent it is to galvanize it by adding a coat of zinc to the surface before painting. The amount of zinc is key. A G-100 coating (1 oz. of zinc per sq. ft.) makes a long-lasting substrate for roofing, says Ken Gieseke, vice president of marketing at McElroy Metal, a Louisiana-based manufacturer. Galvalume is another, and widely regarded as better, option. In this process, bare steel is coated with an alloy of zinc and aluminum (generically, this coating is referred to as an AL-Zn alloy) before it’s painted or clear-coated. The treatment is especially useful in harsh weather conditions. McElroy cites a side-by-side comparison in which Galvalume- coated panels were two to four times as durable as galvanized steel after 23 years of weather exposure.
More about metal roofing:
Snap-Lock Standing-Seam Metal Roof Installation – Factory-made panels and flashing go together without specialty tools or subcontractors.
A Home Completely Wrapped in Metal Roofing and Siding – Bridger Steel’s standing seam metal roofing and siding creates clean lines for a modern exterior
From FineHomebuilding #289
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