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an aircraft's wing. The roof in effect becomes an airfoil that is <br /> attempting to "take off" from the rest of the building. Roof <br /> vortexes generally concentrate the wind's uplift force at the <br /> corners of a roof. These key points can experience uplift <br /> forces two to five times greater than those exerted on other <br /> parts of the roof. <br /> Once the envelope of the building has been breached through <br /> the loss of a window or door, or because of roof damage, wind <br /> pressure on internal surfaces becomes a factor. Openings <br /> may cause pressurizing or depressurizing of a building. <br /> Pressurizing pushes the walls out,while depressurizing will pull <br /> the walls in. Internal pressure coupled with external suction <br /> adds to the withdrawal force on sheathing fasteners. <br /> Damages from internal pressure fluctuations may range from <br /> blowouts of windows and doors to total building collapse due to <br /> structural failure. <br /> During Hurricane Andrew, catastrophic failure of one-and two- <br /> story wood-frame buildings in residential areas was observed <br /> more than catastrophic failures in other types of buildings. <br /> Single-family residential construction is particularly vulnerable <br /> because less engineering oversight is applied to its design and <br /> construction. As opposed to hospitals and public buildings, <br /> which are considered "fully engineered," and office and <br /> industrial buildings, which are considered "marginally <br /> engineered," residential construction is considered <br /> "non-engineered." Historically, the bulk of wind damage <br /> experienced nationwide has occurred to residential <br /> construction. Fully engineered construction usually performs <br /> well in high winds due to the attention given to connections and <br /> load paths. <br /> Hurricane winds generate massive quantities of debris that can <br /> easily exceed a community's entire solid waste capacity by <br /> three times or more. Debris removal is an integral first step <br /> toward recovery, and as such, must be a critical concern of all <br /> those tasked with emergency management and the restoration <br /> of community services. <br /> A storm surge is a large dome of water often 50 to 100 miles <br /> wide and rising anywhere from 4 to 5 feet in a Category 1 <br /> hurricane and up to 20 feet in a Category 5 storm. The storm <br /> surge arrives ahead of the storm's actual landfall, and the <br /> Indian River County Comprehensive Emergency Management Plan Basic Page 15 <br />