Wind Mitigation: What Is It?
Wind mitigation refers to special construction features that prevent or reduce damage and loss to your home caused by extremely strong winds. In hurricane-prone Florida, wind mitigation strategies are essential to protect your home and family. These precautions can also save you money on your homeowners insurance.
Here are some of the most common ways to protect your home from the devastating effects of hurricanes and ensuing water damage.
You may not have given much thought to the shape of your roof, but its slopes and angles directly impact your roof’s ability to withstand the intense uplift pressure that hurricane-force winds exert on buildings. If you’re building a new home, it will pay off in the long run to install a roof that will stand up to strong winds, protect your home and family, and earn you credit on your homeowners insurance.
Roofs with multiple slopes, such as hip roofs (four slopes), performed better in wind tunnel tests than those with fewer slopes, such as gable roofs (two slopes). The degree of the roof slope also matters: A 30-degree slope garnered the best results in tests. Hip roofs are subjected to up to 40 percent less wind pressure during a hurricane than gable roofs. Therefore, full hip roofs qualify for insurance discounts. Florida building code requires the installation of gable-end bracing in gable roofs on newly built and reroofed homes.
Type of Roof
Lightweight, affordable, three-tab asphalt shingles are a popular choice for Florida homeowners, but they are rated for wind speeds of only 60–70 mph, which is the speed of a tropical storm and not even a Category 1 hurricane. Heavier shingles, also known as architectural or dimensional shingles, are usually rated for winds up to 110 mph, which is the high end of a Category 2 storm on the Saffir-Simpson scale. The wind rating for these shingles can be increased to 130 mph (through Category 3) by employing one of the following installation techniques:
- Using 6 nails instead of the standard 4
- Using strategically placed dabs of asphalt roofing cement
- Using additional fasteners on the last shingle at the peak or ridge plus roofing cement
Standing seam metal roofs are excellent at repelling wind, water, and wind-blown debris, and some brands have been rated up to 160 mph (Category 5). Stone-coated steel roofs are extremely durable and offer wind resistance up to 120 mph (Category 3). Clay and concrete tiles, popular with many Florida homeowners, offer great hurricane protection can sustain winds as high as 125 miles per hour as long as they are properly installed. Natural slate is a heavy, durable material that, while costly, has proven to be an excellent material in high-wind zones.
The roof deck is the part of your roof that is attached directly to your home's rafters or trusses and onto which the roofing material is laid. A properly installed roof deck is plywood or oriented strand board (OSB) that is at least 7/16 inches thick and is attached with 8-penny (8d) common nails that are at least 2.25 inches long and are spaced at least 6 inches on center on the edges and 12 inches on center in the field.
Secondary Water Barrier
Florida building code requires that an approved self-adhering polymer modified bitumen sheet be attached to the roof deck to act as an additional water barrier to provide extra protection in case your shingles are compromised in a storm.
Hurricane Fasteners (Clips or Straps)
Fasteners connect roof trusses or rafters to the tops of walls. In order to be effective and to qualify your home for an insurance discount, clips or straps must be properly installed, have three nails securing them, and be free of corrosion or rust. Installing hurricane fasteners is a job best left to a professional, as there is very little room to maneuver in an attic at the edge of a pitched roof.
Shutters come in many shapes and materials. The most common kind are interlocking, corrugated, aluminum panels that slide into permanent, pre-mounted tracks around windows. Steel roll-down shutters, which can be manually or electrically operated, are the costliest option. Bahama- and Colonial-style shutters add architectural style but offer less protection than other types.
So-called impact windows are composed of a layer of plastic between two pieces of extra-strong glass. Even if the glass cracks or breaks, the plastic protects the pane from breaking open and letting wind infiltrate your house, which will eventually cause the inside air pressure to build until the entire structure fails.
A Wind Mitigation Inspection Saves You Money on Your Homeowners Insurance
Florida law requires insurance companies that offer residential property insurance to offer hurricane windstorm coverage to homeowners. Florida law also requires insurance companies to offer discounts and credits on the hurricane windstorm part of insurance premiums to homeowners who install wind mitigation features in their homes. In addition, in order to be approved for a mortgage, Florida homeowners are required by banks and other lenders to carry windstorm insurance.
Oddly enough, homeowners in hurricane-prone Florida, with its 1,350 miles of coastline, are not required by law to have wind mitigation inspections done for their homes, but insurance companies do require these inspections for homeowners to qualify for policy discounts. And it certainly is to every homeowner's benefit to do so. Typically, these discounts add up to significant savings over time that more than pay for the mitigation features installed as well as for inspections.
Glad You Asked
How much does a wind mitigation inspection cost?
A wind mitigation inspection in the Sarasota and Bradenton areas typically costs $75–$150, depending on your home’s square footage.
How long is it good for?
An inspection report is good for five years.
What does it entail?
A licensed home inspector inspects your roof, attic, openings, and eaves. He then completes the wind mitigation form required by insurance companies, which covers these key areas:
- Year your home was built
- Roof shape or geometry
- Roof bracing of gable end (if applicable)
- Roof deck attachment
- Roof covering
- Roof-to-wall connections
- Secondary water resistance
- Doors (including garage doors)
- Protection of openings (windows, doors, skylights, etc.)
To qualify for insurance discounts in various categories, your home must be 100 percent compliant. If, for example, all of your home’s windows are impact resistant except one, you won’t qualify for a discount in the category that covers protection of openings.
How much can I save on my insurance?
Many homeowners can save up to 60% on the hurricane windstorm part of their insurance premiums.
How do I find an inspector?
AKVM can refer you to a licensed home inspector in the Sarasota and Bradenton areas who is an expert in wind mitigation features and techniques.
Call us today at 941-727-3996 for a referral.