A wind mitigation is a strategy designed to limit the amount of wind damage inflicted on a structure. Various incentives are in place to motivate homeowners to implement these enhancements, and qualified inspectors can determine which improvements are necessary.

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Checklist for Wind Mitigation Techniques:

• garage doors:  These commonly fail during windstorms due to:

  • inadequate door-track strength and mounting systems; and

  • flimsy metal panels.                       

     The following features can protect a garage door from wind damage:

• • no windows;

    • track brackets that are securely attached to the wall; and

• horizontal and/or vertical reinforcement on all panels.

• opening protection:  Glass doors and windows should be replaced with impact-resistant glass. They should be structurally attached to the building in order to prevent the entire window from popping out of its frame. Sliding glass doors are especially vulnerable to flying debris due to their large expanse. Once an opening is created during a windstorm, the pressure within the house can rise high enough to cause the roof to fail in areas of low pressure. The picture to the right demonstrates how these areas of low pressure can form. 

• roof covering: There are many kinds of roof covering materials, and some resist wind damage better than others. The most common roof covering materials in Florida are composition shingles and tiles. A key factor in roof covering performance is the method of attachment of the roof covering material to the roof deck. Nails, not staples, should be used to fasten these materials.

• roof shape:  "Roof shape" refers to the geometry of the roof, rather than the type of roof covering. The end-walls of gable roofs extend vertically to the sloping roofline. These gable end-walls, if not properly built or braced, have been known to fail outward due to the negative suctions on the wall. Additionally, field testing has shown that hip roofs receive up to 40% less pressure from wind than gable roofs.

• roof deck attachment:  According to insurance claim data, a house becomes a major loss once the roof deck fails, even partially. The most common roof deck types are plywood and OSB. The most important feature of the roof deck by far is the attachment to the framing compared to the deck's thickness. The following building techniques can help prevent wind damage:

  • roof coverings using shingles that meet the FBC requirements;            

  • roof decks that have been installed with large nails and close spacing; 

  • hurricane clips/straps that hold the roof structure to the walls; and 

  • protection of windows and glass doors with impact-resistant glazing or other protection systems.

• roof-to-wall connections:  This connection is a critical safeguard that keeps the roof attached to the building and acts to transfer the uplift loads into the vertical walls. This connection is crucial to the performance of the building due to the large negative pressures acting on the roof. Proper installation is essential to connector performance.

• secondary water resistance: This is a layer of protection that shields the home in the event that the roof covering fails. It will reduce leakage if the shingles are blown off. A secondary water barrier is relatively rare in homes. The two most common types are:

  • self-adhering modified bitumen underlayment, which is applied to the exterior of all joints; and

• foam seal, which is sprayed onto the underside of the decking.

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