Study of wind loads on asphalt shingles using full-scale experimentation

Abstract

Asphalt shingles constitute more than 80% of the roofing materials in current residential housing in the United States. Many post-disaster surveys have reported the failure of these roofing elements below the design level wind event. Research to realistically model the aerodynamics of asphalt shingles at full-scale is limited, resulting in knowledge gaps in peak wind loads and effects of permeability. In this study, the aerodynamics and wind resistance of asphalt shingles are studied by using a monoslope roof tested at Florida International University's Wall of Wind Experimental Facility. Results from both aerodynamic and failure assessment test protocols showed that shingles near the upper corners of the roof were subjected to high suctions due to cornering winds. This presents a critical loading case for which asphalt shingle roofing systems are not typically tested using current standard tests. Moreover, the extent of permeability underneath the shingles was observed to vary with the spatial location of shingles and wind direction. Finally, the comparison of area-averaged peak Cp values obtained from this study with GCp plots in ASCE 7-16 Standard showed that these provisions, which do not consider the effects of permeable roofing elements (e.g., shingles), can underestimate wind loads on asphalt shingles.