Performance of Asphalt Shingles under Simulated Hurricane Winds and Evaluation of Current Installation Practices

This paper investigates the wind resistance of asphalt shingles, evaluates the efficiency of their current installation methods, and addresses the lack of a system-level resistance metric from a wind engineering standpoint. The study examined the wind performance of asphalt shingles considering three installation practices recommended in high-velocity wind areas and three nailing non-conformities due to workmanship issues by conducting full-scale failure assessment tests at the NHERI Wall of Wind Experimental Facility. Roofing Application Standard (RAS) No. 115 and FEMA's recommended practices, with and without modifications, were used as recommended practices; while missing nails, over-driven nailing, and high-nailing cases were simulated as installation deviations or errors. Monoslope, gable, and hip roof decks were also used to study the contribution of roofing geometries. The results showed that asphalt shingles installed using methods recommended by the current guidelines may be vulnerable to wind flows from critical directions. Asphalt shingles, tested in the current work, experienced failure at wind speeds below their design level, especially due to cavity pressurization. Nailing non-conformities were also observed to compromise shingles' performance. Additionally, asphalt shingle failure modes, extents, and areas varied with roof geometries and the employed installation methods.