Building Loading - Wind Exposure ( MAST (5th), KS, MAST(6th) )
Exposure A: Centers of large cities and very rough, hilly terrain. Exposure A applies for downtown areas only when the terrain for at least one-half (1/2) mile upwind of the structure is heavily built up, with at least fifty (50) per cent of the buildings being in excess of four stories and when Exposure B prevails beyond this boundary. Exercise caution in using these reduced wind pressures for buildings and structures on high ground in the midst of cities or rough terrain.
Exposure B: Suburban areas, towns, city outskirts, wooded areas, and rolling terrain. Exposure B applies only when the terrain for at least one (1) mile upwind is a continuous urban development, forest, wooded area, or rolling terrain.
Exposure C: Open, level terrain with only scattered buildings, structures, trees, or miscellaneous, obstructions, open water, or shorelines.