The maxim, “Everybody complains about the weather, but nobody does anything about it,” is no longer merely ironic. Those frustrated by government, industry and diplomacy in addressing the root causes of climate change may feel a genuine sense of urgency to do something about the weather themselves.
Extreme weather events, including heat waves, high winds and heavy downpours, have increased in frequency and become more widespread as a result of global warming, according to a U.S. government report entitled “Climate Change Impacts in the United States.” Incidentally, extreme weather is also the leading cause of roof failure.
While it may seem like little will be done to arrest the extreme weather trend, at least one community is doing something constructive in response. Dade County, Florida—which has endured the effects of a series of catastrophic hurricanes over the last generation—has developed codes for roofing installation that are saving property and lives.
As events like Superstorm Sandy and the recent Hurricane Joaquin threaten the Eastern Seaboard and the Northeast, it’s wise to take a hint from a state like Florida, where high winds and hurricanes are nothing new, when preparing for a roof installation or inspecting the strength of your current roof.
Florida Statute 553.88 is pretty dry reading, so let’s summarize the key points:
- Inspect connections between wall frames and roof framing members, and if not present, install approved connectors at spacing intervals recommended to withstand the maximum uplift possible for your roof in your area.
- Existing roofing should be stripped down to the sheathing so that it can be inspected for appropriateness of type, decay and adherence to more stringent fastening requirements.
- Gaps between spaced sheathing boards should be filled with sound material of the same thickness, or replaced with ½-in. (min.) plywood or OSB panels. Metal drip edges should be applied to sheathing edges along rakes and eaves with screws spaced no more than 12 in. apart.
- Sheathing panels should be fastened with 8d galvanized ring-shank nails 2-1/2 in. long, spaced no more than 6 in. OC (on-center) along edges and no more than 12 in. OC within panel interior areas. Weather-proof screws are even better than nails for sheathing.
- Roofing systems should have a secondary water barrier covering all sheathing joints with 4-in. wide self-adhering bituminous tape, followed by covering with an approved self-adhering bituminous base sheet.
- In high-wind areas, each shingle should be fastened with six galvanized roofing nails long enough to penetrate through sheathing at least ½-in.
- All shingle butts should be firmly bonded to the course below with self-sealing adhesive or manually-applied roof cement.
The Climate Change Impacts report predicts that extreme weather events will continue to increase in frequency and intensity in coming years and spread to areas where they have not previously occurred. Wherever you live, Dade County’s requirements may be smart recommendations for your own home.
If you’re unsure of your own roof’s strength and durability, have it inspected. Choose a contractor or installer who offers a strong warranty and stands by their work (and is licensed and insured, of course), and look for someone backed by a well-known and respected brand in your area. If you discover that your roof is weak, remember that a replacement roof could literally protect the rest of your house in the event of an extreme weather event.
Roofing expert Michael Chotiner has years of hands-on experience as a general construction contractor and cabinet maker and writes for The Home Depot.