Wind Uplift Behavior of Mechanically Attached Single-Ply Roofing Systems: The Need for Correction Factors in Standardized Tests

Abstract

In the United States, currently there are three consensus test methods for determining the wind uplift capacity of mechanically-attached single-ply roofing membrane systems. Each is based upon a specific specimen size and static loading regime. However, few studies have examined the relationship, if any, of failure loads among these methods. This study was conducted to determine the effects of varying specimen sizes on the static wind uplift performance or failure loads of mechanically-attached single-ply roofing membranes. Full-scale wind uplift pressure tests were performed in three phases, using six specimen sizes, and three membrane materials. The results were used to determine the minimum acceptable specimen sizes to be used for testing. In Phase 1, fastener failure loads were monitored, while in Phases 2 and 3, the failure experiments were repeated without measuring fastener loads. A significant difference in the apparent failure loads occurs among different specimen sizes for the same membrane materials. The results suggest that correction factors are necessary for comparing tests on different test beds and that the performance of membranes in the test chamber may not produce the same results on full scale structures.