Overview of Wind Damage to Woodframe Structure Caused by Hurricane Katrina: Fid-Bau Portal

Overview of Wind Damage to Woodframe Structure Caused by Hurricane Katrina

Graettinger, Andrew J. / van de Lindt, John W. / Gupta, Rakesh / Pryor, Steven E. / Skaggs, Thomas D. / Fridley, Kenneth J.

Abstract

Hurricane Katrina, the most costly natural disasters in U.S. history, made landfall on August 29, 2005 at 7:10 a.m. local time in Plaquemines Parish, LA. Although Katrina caused widespread damage and loss of life, it also provided an opportunity to evaluate how woodframe construction performed in a naturally occurring high wind speed environment. A team of researches from across the country, sponsored by the National Science Foundation, conducted a three day study that investigated 27 sites containing woodframe structures along the Gulf Coast of Mississippi. Sites included entire subdivisions, light commercial structures, multifamily apartment buildings, and singe family homes. Observed wind induced damage at these sites included the loss of a few shingles, loss roof sheathing, loss of siding or brick veneers, porch collapses, roof loss, and also woodframe building collapse. The goal of this study was to examine wind damage in detail, determine the failure mechanisms when ever possible, and provide recommendations for individuals and organizations involved in the woodframe structure industry. Results of this investigation indicated that woodframe residential and light commercial structures that followed design codes and guidelines performed well during hurricane Katrina's wind loading. It appeared that builders and inspectors were familiar with conventional construction provisions; however, these provisions were used erroneously at times in this high wind region along the Gulf Coast. Where failures occurred, careful attention was not paid to all details, particularly the (correct) use of all straps and ties, to ensure a continuous load path from the roof to the foundation. It was observed that architectural shingles tended to remain intact more often that regular roof shingles and a closer/heavier nailing schedule for roof sheathing would reduce the amount of roof sheathing loss. Seemingly insignificant details such as the proper connection of non-structural siding resulted in the loss of siding followed by the loss of foam board substrate that allowed rain water intrusion and major damage. The information gained from this study will be useful to design engineers, owners, building material manufactures, builders, and building code officials whom are all striving to produce improved woodframe structures.