Which zone is associated with the lowest uplift pressures?

Which zone is associated with the lowest uplift pressures?

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

Answer: (C)

Wind uplift on a roof varies by location: corners and edges experience stronger suction, while the center feels the least. This happens because airflow around corners creates strong vortices and accelerated flow that pull more on the roof edges and corners. As you move toward the middle of the roof, the flow becomes more uniform and pressures approach ambient, resulting in less suction. So, the center (field) zone has the lowest uplift pressures. In practice, this means the field zone typically requires less securing than the perimeter or corner zones, which are more critical for fastening.

Wind uplift on a roof varies by location: corners and edges experience stronger suction, while the center feels the least. This happens because airflow around corners creates strong vortices and accelerated flow that pull more on the roof edges and corners. As you move toward the middle of the roof, the flow becomes more uniform and pressures approach ambient, resulting in less suction. So, the center (field) zone has the lowest uplift pressures. In practice, this means the field zone typically requires less securing than the perimeter or corner zones, which are more critical for fastening.