At what angle to the length of the shingle is an asphalt shingle most resistant to wind?

Asphalt shingles are designed to withstand wind forces and their resistance is significantly influenced by their orientation relative to the direction of the wind. When shingles are installed at an angle of 90 degrees to the wind direction, this maximizes their resistance because the wind flows over the shingles in a manner that reduces the potential for uplift.

At this angle, the flat surface of the shingles effectively deflects the wind, allowing the wind to flow smoothly over them instead of getting underneath and creating pressure that could lift the shingles. This design takes advantage of aerodynamics, as the 90-degree orientation minimizes the likelihood of wind catching edge portions of the shingles, which could lead to loosening or detachment.

In contrast, when shingles are aligned at 0 degrees (parallel to the direction of wind flow), they are more susceptible to being lifted as the wind can easily get underneath the shingles. Angles like 45 degrees and 180 degrees would also not provide optimal resistance, as they either create equivalent pressures that are detrimental to the shingle's adherence or fail to properly deflect the wind efficiently. Understanding the dynamics of how wind interacts with roofing materials is crucial for ensuring effective roof performance and longevity.