Caribbean Disaster
Mitigation Project
Implemented by the Organization of American States
Unit of Sustainable Development and Environment
for the USAID Office of Foreign Disaster Assistance and the Caribbean Regional Program
HURRICANES
Wind generating opening on the windward side during a hurricane will increase the pressure on the internal surfaces. This pressure, in combination with the external suction, may be sufficient to cause the roof to blow off and the walls to explode.
During a hurricane an opening may suddenly occur on the windward side of the house. The internal pressure which builds up as a result may be relieved by providing a corresponding opening on the leeward side.
Failure of the Wall: Wind forces on the walls of the house may produce failure. Wind striking a building produces pressure which pushes against the building, on the windward side, and suction which pulls the building on the leeward side and the roof. If no air enters the building, then there is pressure inside which is pushing against the walls and the roof.
Another mode of failure occurs when the windward side of the house collapses under the pressure of the wind.
If the building is not securely tired to its foundations, and the walls cannot resist to push/pull forces the house tends to collapse starting the roof with the building leaning in the direction of the wind.
Overturning is another problem for light structures. This occurs when the weight of the house is insufficient to resist the tendency of the house to be blown over.
All modes of failure can be avoided by bracing timber structures and reinforcing the concrete walls.