Wind mitigation is the use of certain building techniques that limit damage caused by intense wind, such as hurricanes. Here in the Jacksonville and St. Augustine areas, our homes and businesses are at risk for damage by wind not just during hurricane season, but in the winter, as well. Wind mitigation has become increasingly important for homeowners in the Jacksonville region, as insurance companies look to decrease their risk, Some insurance companies will raise rates for homeowners who do not meet the latest state standards for wind mitigation. There are also some incentives available to help St. Augustine and Jacksonville homeowners make improvements to their homes for wind mitigation. This is the only inspection that can help lower your homeowner’s insurance.
A Few Facts About Windstorms and Wind Insurance:
In 2006, Citizens Insurance, one of the largest property insurers in Florida, requested a 45% rate increase for wind insurance. Other insurers took similar actions.
In Florida, the portion of a home owner’s premium covering wind damage can be up to 70% of the total, depending on the location.
Wind mitigation benefits homeowners, private insurers, and all levels of government.
Incentives for Wind Mitigation:
Checklist for Wind Mitigation Techniques:
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;
- the tracks for the door that have six to nine mounting brackets, or continuous mounting;
- track brackets that are securely attached to the wall; and
- horizontal and/or vertical reinforcement on all panels.
Glass doors and windows should be replaced with impact-resistant glass. They should be structurally attached to the building 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.
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” 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.
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.
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.
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.
In 2009, InterNACHI developed a wind mitigation certification program for inspectors. It is approved by most insurance companies and the Florida Construction Industry Licensing Board. Inside & Out Property Inspectors, Inc. has completed this additional training and is certified to conduct wind mitigation inspections.