Wind Effects on Single‐Ply Roofing Systems

Abstract

A failure mechanism for single‐ply roofing systems is formulated that accounts for air infiltration into the space underneath the inflated membrane and the billowing of the membrane with the fluctuations of wind pressure on the roof. The governing differential equation, expressed in terms of the pressure underneath the inflated membrane, is derived and solved numerically for a range of material, geometric, and wind parameters. The results are expressed in terms of a transient response factor (TRF), which is equal to the ratio of the fluctuating component of pressure across the membrane thickness to the fluctuating component of wind pressure. The results show that TRF increases with the rate of air infiltration into the space underneath the inflated membrane, the stiffness of the membrane, the magnitude of the fluctuating component of wind pressure, and the size of the inflated membrane. The inadequacies of the present empirical design procedures are discussed.