Latest International Building Code Change Simplifies Selection of Asphalt Shingles To Meet High-Wind Zone Requirements

Washington, D.C. – Architects, builders and code officials seeking the proper shingle to meet performance requirements in high-wind zones can now find the answer in the 2004 Supplement to the International Building Code (IBC).

After 14 years of research and analysis measuring the performance of asphalt shingles in high wind situations, two standards addressing high-wind test methods and uplift resistance have been included in the 2004 IBC Supplement. These standards in turn form the foundation for a simple-to-use classification method for matching asphalt shingles to wind-speed zones: Class D shingles are suitable for use in 90 mph wind zones; Class G shingles for 120 mph wind zones, and Class H shingles for 150 mph wind zones.

Officials of the Asphalt Roofing Manufacturers Association (ARMA) say they expect shingle manufacturers to begin testing and labeling shingles for the new high-wind classifications in the coming months. Testing is being conducted by ARMA member companies through approved laboratories or testing facilities.

“The asphalt roofing industry has worked long and hard developing the testing and engineering analysis that led to these groundbreaking high-wind standards,” says ARMA executive vice president Russell Snyder. “Until now many jurisdictions were at a loss trying to determine the proper shingle for high-wind areas, given the lack of code clarity and the lack of advanced testing methods. All of that is a thing of the past with these new standards and the code changes.”

The key to determining the high-wind classification of an asphalt shingle is based on its measured resistance to the uplift force of wind at differing speeds. The new standards introduced in the 2004 building code Supplement -- ANSI/UL 2390, “Test Method for the Wind Resistance of Asphalt Shingles with Sealed Tabs” and ASTM D6381 “Measurement of Asphalt Shingle Mechanical Uplift Resistance” – take into account such variables as wind speeds, building height, building exposure, sealant uplift resistance, and the specific fastening recommendations of the shingle manufacturers.

The Asphalt Roofing Manufacturers Association is the North American trade association representing the manufacturers and suppliers of bituminous-base residential and commercial fiberglass and organic asphalt shingle roofing products, roll roofing, built-up [BUR] roofing systems, and modified bitumen roofing systems. For additional information concerning ARMA, its programming and activities, contact ARMA at: [202] 207-0917; fax: [202] 223-9741; or visit the ARMA web site at: www.asphaltroofing.org.

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