Which roof zone experiences the highest uplift pressures?

• A. Center Zone
• B. Field Zone
• C. Corner Zone
• D. Perimeter Zone

Answer: (C)

The strongest suction on a roof comes from how wind flows around corners. When wind meets the edge and wraps around the corner, flow accelerates and corner vortices form, concentrating negative pressure on the roof surface at that point. The center of the roof is comparatively sheltered by surrounding surfaces, so the uplift there is less extreme, and the perimeter, while still significant, doesn’t reach the same peak as the corner. Because of this concentrated suction at the intersection of two roof planes, the corner zone experiences the highest uplift pressures. This is why corner detailing and fastener strategies are critical for wind resistance.