Why Metal Roofing Is the Better Choice

RSI EXTRA NEWS, February 7, 1991
By: V. Snnivasan, General Sales 8 Marketing Manager, Englert Inc.

THE 1989 RESIDENTIAL roofing market has been estimated at 11 billion square feet by a recent study. That translates to a $5 billion market. Asphalt shingle covering makes up 86 percent of the residential roofing market. Concrete and clay tiles cover another eight percent. Wood shakes/shingles represent another four percent, with metal roof taking less than one percent of the total market share.

Yet metal offers several distinct advantages over other roofing substrates. In terms of weight, metal is a light weight substrate. It weighs about 40 to 120 pounds per square as opposed to asphalt/fiberglass shingles at 210 to 350 pounds per square, wood shingles at 200 to 300 pounds per square (400 – 600 pounds per square when wet), and clay/cement tiles that weigh 800 to 1,000 pounds per square.

Metal offers a light roof for pre-owned homes with structural weakness. In new construction, it offers savings in the structural design of a home because of its light weight.

Metal has outstanding fire resistance qualities. Metal will not burn or support combustion from any source. It qualifies for a Factory Mutual Class A fire rating, unlike asphalt and wood shake shingles which are combustible. For this reason, wood shingles have been banned in residential construction in parts of California. This advantage of metal roofing could be reflected in lower insurance rates and fewer home fires initiated by wind-born sparks.

Metal roofing has greater wind resistance than some other products. Metal roofs can withstand 90 plus miles per hour wind velocity compared to wood singles at 50 to 60 miles per hour or asphalt/fiberglass at 60 to 70 miles per hour. Metal roofs will not need periodic repair or replacement or maintenance because of wind or storm damage.

Metal roofs have the lowest rate of water absorption -- less than one percent compared to wood shingles at 100 percent, asphalt/fiberglass shingles between 10 to 20 percent and cement and clay tiles at 5 to 10 percent. Water absorption by roofing products tends to damage roofing substrates by rotting, cracking or freeze/thaw cycling, eventually causing roof failure or replacement.

Metal roofs are the most energy efficient in that they reflect radiant heat, reducing cooling requirements up to 40 percent. While clay/cement tiles and shakes and shingles offer very minimal insulation value, asphalt shingles even absorb radiant heat, increasing cooling requirements.