On flat concrete rooftops, small raised turrets (stairwell or machine rooms) are often used to add photovoltaic capacity when the main roof is full. Installers frequently lay panels flat at 0 degrees on these turrets, fearing high wind catch. Yet flat mounting visibly cuts yield and worsens soiling.

On concrete flat roofs, distributed rooftop solar arrays often use precast concrete ballast blocks instead of roof penetrations. These blocks resist wind through gravity: their dead weight creates a restoring moment against uplift and sliding forces acting on the modules and rails. Wind performance