Windstorms Come in Numerous, Damaging Forms
How Windstorms Damage Roofs
Windstorms are high-speed gusts or strong, sustained winds exceeding 34 miles per hour1. They’re strong enough to inflict light-to-severe damage on trees and buildings, and can be accompanied by rain, snow, or hail. Some windstorms last for a few minutes, as when caused by thunderstorm downbursts; others can go on for hours or even days when part of a large-scale weather system.
Forceful winds can directly loosen or blow off roofing materials. Indirectly, windstorms can hurtle debris into a structure, or cause trees or tree limbs to fall onto homes. Damaged roofing compromises a roof’s waterproofing integrity and makes a home susceptible to moisture infiltration that can cause leaks and interior mold growth.
How to Prepare and Recover from Windstorm
If you’re expecting a windstorm, examine your roof for any weak points or trouble signs like loose shingles or flashing. If you spot any areas of concern, contact a professional to make necessary repairs or replacements. To guard against flying objects shattering your windows, install metal storm shutters. You could also use plywood panels to protect your windows2.
Garage doors are susceptible to high wind damage, too. If your garage door is showing signs of wear and tear, you may want to contact a firm that installs garage doors and schedule an inspection.
Heavy winds can bring down trees and branches. Consider trimming tree branches that hang over your house, or even taking down trees that are dangerously close to your home. You should also store or secure outdoor furniture or appliances: patio furniture, grills, outdoor decor, and even your garden shed or kids’ playhouse. Move what items you can inside and consider securing items too big to move by attaching them to anchors using steel cables or chains.
After a windstorm passes, keep safety foremost in mind as you assess property. Steer clear of downed power lines, trees with hung up broken limbs, and home areas with visible structural damage. Contact your insurance company, local utilities, and other professionals to handle these hazards.
Depending on the amount of roof damage, you may simply need repairs. Or you may suddenly find yourself in the market for a new roof. Either way, you’ll want to find a reputable roofing contractor to perform the work. You’ll also want your new roofing to have a high wind-resistance rating to protect you in future storms. Fortunately, many roofing products sold today offer wind resistance ratings of 110 mph or more when installed to manufacturer specifications.
Windstorm Facts
In the lower 48 states, damage from severe thunderstorm winds is more common than damage from tornadoes. Wind speeds can reach up to 100 mph and can produce a damage path extending for hundreds of miles3. A widespread, long-lived windstorm associated with a band of rapidly moving showers or thunderstorms is called a derecho — a Spanish word that means “right” but travels straight. Derechos can cause widespread damage to developed and undeveloped areas, typically in one direction along a relatively straight path (known as straight-line winds).
A July 4, 1999, derecho in Minnesota with winds estimated between 80 and 100 mph completely flattened nearly 500,000 acres of the Superior National Forest4.
How Windstorms Form
Windstorms form when opposing weather systems cause a center of low air pressure to develop while a system of high air pressure surrounds it. Windstorms come in multiple forms: thunderstorms, low pressure weather systems, and air moving over the major mountain ranges of the western U.S. can all give rise to high winds. Bands of thunderstorms that move together and create derechos are most common in the Midwest5.
Sources:
1. https://www.britannica.com/science/windstorm
2. https://www.thisoldhouse.com/windows/21015378/emergency-window-board-up
3. https://www.nssl.noaa.gov/education/svrwx101/wind/
4. https://www.weather.gov/dlh/July_4_1999_BWCA_Storm
5. https://mylandplan.org/content/what-when-and-where-windstorms
