Exposure categories in wind design are used to determine which of the following?

Exposure categories in wind design are used to determine which of the following?

• A. Wind loads on the roof
• B. Color selection
• C. Drainage
• D. Thermal resistance

Answer: (A)

Exposure categories describe how the surrounding terrain and nearby obstructions affect wind flow around a building, which in turn changes the wind pressures acting on the roof. The category you choose reflects how exposed the site is to wind and how much the wind speed and turbulence are dampened or amplified by the surroundings. Those wind pressures are what you use to compute the roof’s design wind loads, so the category directly determines the wind loads on the roof. Color selection, drainage performance, and thermal resistance are not dictated by exposure categories.

Exposure categories describe how the surrounding terrain and nearby obstructions affect wind flow around a building, which in turn changes the wind pressures acting on the roof. The category you choose reflects how exposed the site is to wind and how much the wind speed and turbulence are dampened or amplified by the surroundings. Those wind pressures are what you use to compute the roof’s design wind loads, so the category directly determines the wind loads on the roof. Color selection, drainage performance, and thermal resistance are not dictated by exposure categories.