New Tornado Specification Released

April 26, 2011

As tornado season escalates and increased tornado activity has devastated parts of the Midwest and the South during the past few weeks, the American Architectural Manufacturers Association has released a voluntary specification for testing and rating windows and other fenestration products that will be exposed to tornados and similar extreme wind and rain conditions. 

AAMA 512-11, Voluntary Specifications for Tornado Hazard Mitigating Fenestration Products, uses existing test methods and other procedures to qualify windows and other glazed fenestration products for tornado hazard mitigation, officials point out. The newly-released document provides a system for rating the ability of windows to withstand impact, pressure cycling and water penetration, which are generally associated with tornado conditions.

“The National Climatic Data Center estimates that a series of tornados in the Southeast and Ohio Valley in February 2008 caused $1 billion in damages,” says Gantt Miller of Winco, who chaired the task group that created the specification. “In creating this specification, the intent is that injury, loss of life and damages resulting from tornados and severe weather can be prevented or greatly lessened.”

The specification outlines that different levels of protection apply to different buildings such as, but not limited to, hospital emergency rooms, community shelters, and police/fire headquarters. These levels of protection are specified based on requirements of the authority having jurisdiction, and each level corresponds to different testing requirements. The level of testing required for each of these types of facilities also depends on the FEMA performance zone where the building is located, as the weather conditions and likelihood of a tornado varies depending on the part of the country.

More information on purchasing the AAMA 512-11 is available at the organization's online publication store.