Rank the uplift pressures from lowest to highest among Field, Perimeter, and Corner zones.

Rank the uplift pressures from lowest to highest among Field, Perimeter, and Corner zones.

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

Answer: (D)

The idea being tested is how wind-induced uplift varies across a roof surface: suction is smallest in the middle and grows toward the edges, peaking at the corners. In the field, the airflow is relatively uniform, giving lower suction. As you move to the perimeter, flow accelerates along the roof edge, increasing the suction there. At the corners, wind wraps around two edges and creates corner vortices, which intensify the suction the most. So the order from least to greatest uplift is field (lowest), then perimeter, and finally corner (highest).

The idea being tested is how wind-induced uplift varies across a roof surface: suction is smallest in the middle and grows toward the edges, peaking at the corners. In the field, the airflow is relatively uniform, giving lower suction. As you move to the perimeter, flow accelerates along the roof edge, increasing the suction there. At the corners, wind wraps around two edges and creates corner vortices, which intensify the suction the most. So the order from least to greatest uplift is field (lowest), then perimeter, and finally corner (highest).