Hurricane-proof building

Tornadoes, cyclones, and other storms with strong winds damage or destroy many buildings. However, with proper design and construction, the damage to buildings by these forces can be greatly reduced. A variety of methods can help a building survive strong winds and storm surge. Waves along coastal areas can destroy many buildings. Buildings should preferably be built on high ground to avoid waves. If waves can reach the building site, the building should be elevated on steel, concrete, or wooden pilings or anchored to solid rock. Wind on the roof surfaces can cause negative pressures that create a lifting force sufficient to lift the roof off the building. Once this occurs, the building is weakened considerably, and the rest will likely fail as well. To minimize this vulnerability, the upper structure ought to be anchored through the walls to the foundation. Several methods can be used to anchor the roof. Typically, roof trusses are "toenailed" into the top of the walls, which provide insufficient force to resist high winds. Hurricane ties nail into the wall and wrap over the trusses to provide higher force resistance. Interlocking metal pan roof systems installed on mobile homes can fail under the pressure differential (lift) created by the high-velocity winds passing over the surface plane of the roof. This is compounded by the wind entering the building allowing the building interior to pressurize, lifting the underside of the roof panels, resulting in the destruction of the building. One example of pan roof systems can be found in this document from Structall Building Systems . To mitigate this pressure differential, pre-installed aluminum tabular channels can be permanently fastened perpendicularly across the top of the interlocking ribs of the metal roof system without disturbing the flow of rainwater at the eaves mid-span and ridge locations of the building. Earth-sheltered construction is generally more resistant to strong winds and tornadoes than standard construction.