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What is checked during a wind mitigation inspection?
Saturday, March 7, 2020
There are seven different hurricane-resistant construction details of a home that the inspector looks for in a wind mitigation inspection (Form OIR-B1-1802). Few homes have all of them, but most have at least a few. Here’s our analysis of each of the seven discount categories on the form:
1) Building Code: This discount is given for homes that were built after the first version of the state-wide Florida Building Code took effect in March 1, 2002. For homes in Miami-Dade and Broward counties only, the discount applies if the permit date is after September 1, 1994. The exact date of the permit application must be entered on the form if it is near the year the new codes took effect. Only the date for the original construction of the home is used, and later permits for home additions or roof replacement do not change it. To learn more, see our blog post Which building permit date is used for the Building Code section of the wind mitigation form?
2) Roof Covering: Concerns whether the roof covering material is Florida Building Code or Miami-Dade County approved. Date of roof permit or original construction can be used here, or evidence on shingle of Miami-Dade approval. If any part of the roof does not qualify, you do not get this discount.
3) Roof Deck Attachment: This section notes how the roof sheathing is attached to the trusses or rafters, with levels from “A” (lowest) to “C” (best). The inspector needs unobstructed access to the attic to document and photograph the attachment. Beginning in October 1, 2007, roofing contractors are required to re-nail the roof sheathing using 8d (penny) ringshank nails at 6-inches on center when replacing a roof, which provides the best discount.
If you have a newer roof, you get the “C” discount. Also, homes built since the state-wide Florida Building Code took effect on March 1, 2002, meet the highest standard. The inspector is required to list the weakest connection so, if part of the roof has not been re-nailed to the new standard, it does not get the highest discount. Sheathing attachment with shorter nails or staples, and/or longer spacing than six inches, gets the lesser “B” or “A” discount. To learn more, see our blog post What are the different roof deck attachment discount categories for a wind mitigation inspection?
4) Roof to Wall Attachment: The roof-to-wall attachment ranges from “A” (toe nails, lowest discount), to “B” (metal clip), and then “C” (single wrap strap, best discount for most homes). There is also a “D” category for a strap that wraps from both sides, and “E” for a concrete roof deck—but we rarely see these two attachments. Once again, the weakest form of attachment is the one used; so, if there are both straps and hurricanclips, then clips will be listed. Also, if there are not three nails or the strap/clip is offset at any truss/rafter, then only the “A” discount for toe nails can be given. For more info on this discount, go to our blog post What is the difference between a toe nail, clip, single wrap, and double wrap for the wind mitigation form?
5) Roof Geometry: Because a hip roof is what the insurance industry prefers and gets the best discount, in their lingo there are only three roof shapes: hip, flat, and other. Any roof that is not a hip (slopes inward on all sides to create a pyramid-like shape) and not flat is categorized as “Other Roof”. Also, you do not qualify for the hip discount if more than 10% of the perimeter of the roof, as measured at the fascia, is not a hip. To learn more how a hip roof is defined for insurance, see our blog post How do I get the hip roof discount for my homeowners windstorm insurance?
6) Secondary Water Resistance (SWR): This discount is given for a self-adhering bituminous roofing membrane installed instead of a roofing felt as a base for the roof. It does not require nails to hold it down, and is self-healing of small punctures. A popular brand is Grace Ice & Water Shield®. It’s an expensive option, and you will definitely know if you had it done when your roof was installed. Some homeowners confuse the new synthetic roofing underlayments, such as RhinoRoof®, for secondary water resistance—but they do not qualify for this discount.
7) Opening Protection: We do not inspect for this discount very often in our area of North Florida, because we are not in a wind-borne debris hurricane zone like South Florida. It requires careful documentation by the inspector of any stickers, imprints, or etched markings that specify product approvals. Also, product approval paperwork from the installer can be used to verification if markings on the product are no longer legible. Again, because the weakest area must be used, if only one glazed opening is not protected, the whole discount is voided.
To learn more about wind mitigation options and the approximate discounts provided for them, click on the link below to down the guide “Make Mitigation Happen,” by the Florida Division of Emergency Management.
Here’s links to a collection of our blog posts about the WIND MITIGATION FORM:
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