Code Improvements Adopted Based on NIST Joplin Study
The changes, approved at a recent ICC meeting, apply to the nation's most tornado-prone regions, from northern Texas to central Minnesota and from western Oklahoma to western Pennsylvania.
The International Code Council has approved building code changes based on recommendations from the National Institute of Standards and Technology's investigation of the EF-5 tornado that struck Joplin, Mo., on May 22, 2011, changes intended to protect schools and their related high-occupancy buildings from the most severe tornadoes.
The changes, approved at a recent ICC meeting, apply to the nation's most tornado-prone regions, from northern Texas to central Minnesota and from western Oklahoma to western Pennsylvania. According to NIST's news release, they will require enhanced protection for new school buildings and additions to buildings on existing school campuses, as well as facilities associated with schools where people regularly assemble, such as a gymnasium, theater, or community center. Storm shelters must be provided that protect all occupants from storms with wind speeds of 250 mph, representing the maximum-intensity category EF-5 on the Enhanced Fujita Scale.
The storm shelter requirements will be published in ICC's 2018 International Building Code and 2018 International Existing Building Code.
Based on its investigation, NIST developed 16 recommendations for improving how buildings and shelters are designed, constructed, and maintained in tornado-prone regions, along with improving the emergency communications that warn of imminent threat from tornadoes. "Solid progress is being made working with code developers, state and local officials, U.S. agencies such as the Federal Emergency Management Agency [FEMA] and others toward realizing all of the proposed improvements for tornado protection and resilience in our study," said Marc Levitan, leader of the NIST team that conducted the Joplin investigation. He said current efforts include developing more detailed and more accurate tornado hazard maps for the United States; an improved Fujita scale; draft standards for better selecting buildings to serve as disaster shelters; and guidelines for determining the best available tornado refuge areas in existing buildings.