Uplift Capacity of Light-Frame Rafter to Top Plate Connections

Abstract

An experimental testing program was conducted to investigate the uplift capacity of various rafter to top plate connections. Rather than simply testing the fastener in an ideal test specimen configuration, attention is paid to more realistic test specimens that account for as-built conditions. Consideration is also given to repetitive systems of these connections such as would be found in roof systems. The results from this investigation provide basic data on failure modes and capacities. Comparisons are made between test values, calculated design values, and manufacturers' published values. In addition to metal straps, alternative connection methods such as adhesives are investigated, and consideration is given to both new construction and retrofit of existing structures. The results from this study are used to develop possible schedules for rafter to top plate connections considering different roof slopes, rafter lengths, wind speeds, exposures, and internal pressures.