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Zone 3: The Danger Zone
Watch vortices form at roof corners and discover why this is where roofs fail first during hurricanes.
Why Corners Fail First
As wind flows over the roof and hits the corners, it creates spinning vortices. These vortices act like mini-tornadoes, creating intense suction that can rip off shingles, tiles, and even roof decking.
The Science of Roof Corner Failure
When wind hits your house, it doesn't just push against the walls. It flows up and over the roof like water flowing over a rock in a stream. At the corners, this flow gets disturbed and creates something called "conical vortices."
Think of it like a whirlpool in water, but upside-down on your roof. These spinning vortices create incredibly strong suction - strong enough to lift roof materials that are designed to stay put.
Why This Matters in Monroe County
With design wind speeds of 180 mph, Zone 3 corner pressures can exceed -67 PSF. That's like having a 67-pound weight trying to pull up on every square foot of your roof corner. A 10 ft x 10 ft corner area experiences over 6,700 pounds of uplift force!
This is why building codes require special attention to roof corners. Extra fasteners, stronger underlayment, and sometimes even mechanical attachments are needed to keep the roof attached during a major hurricane.
When you see photos of hurricane damage where just the corners of roofs are missing - now you know why. Zone 3 is where the wind attacks hardest, and it's where your roof needs the most protection.
Calculate Zone 3 Pressures for Your Roof
Get exact corner pressure values for Monroe County building permits
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