Force transfer mechanism on fastener section of mechanically anchored waterproofing membrane roofs under wind pressure during typhoons

The wind pressure, billow of a PVC sheet, and fastener load of a mechanically anchored waterproofing membrane system on a building rooftop were measured during a typhoon. The results showed that the waterproof sheet billowed upward, and the height of the billow was greater on the windward side that was under higher negative pressure. The axial and lateral forces acting on the fastener of the waterproof sheet were measured by a six-component force transducer, and it was found that the lateral force acting on the windward side of the fastener was larger. The tensile force acting on the fastener section was calculated using an equation for rooftop wind pressure. Finally, the method used to determine the fastenerʹs position and the types of materials best-suited to cope with wind pressure on the roof were proposed, and the safety of this waterproof system was evaluated.