What aspect of installation is crucial for the wind performance of asphalt shingles?

The number of nails used in the installation of asphalt shingles is crucial for their wind performance because it directly impacts the shingles' ability to resist uplift and secure them against strong winds. Adequate nailing helps the shingles stay attached to the roof deck, which is essential in preventing blow-off during severe weather conditions. Various building codes and manufacturer guidelines specify the minimum number of nails recommended for different types of shingles and installation methods to ensure optimal performance.

Using the correct number of nails not only secures the shingles but also helps in distributing the stress that winds impose on them. Insufficient nailing can lead to individual shingles becoming loose or dislodged, creating vulnerabilities in the roof system.

While other factors, such as the type of underlayment, overlap of shingles, and direction of shingle alignment, also contribute to the overall performance of asphalt shingles, the number of nails used specifically addresses the bonding strength needed to withstand wind forces, making it a critical aspect of the installation.