Waterproofing membrane used for flat roofs is spot-fastened to the roof deck by fasteners in mechanically attached roofing systems. Therefore, strong stresses act on the attached parts. Furthermore, fluctuating wind pressures may induce fatigue damage to the attached parts. In the design of such roofing systems, it is necessary to evaluate the dynamic effects of wind loading appropriately. Flat roofs generally have parapets, which significantly affect the dynamic wind pressures, particularly in the corner and edge zones of the roof. The purpose of the present study is to investigate the characteristics of fluctuating pressures on flat roofs with parapets, based on a series of wind tunnel experiments and thereby to discuss the wind pressure loading cycles for evaluating the wind resistance of mechanically attached single-ply roofing systems to dynamic wind loading. Focus is on the effect of parapet height on the peak wind pressures and wind pressure loading cycles.