Wind Damage
Asphalt shingles are designed to resist damages from wind – yet, all asphalt shingle roofs will deteriorate with age, and may eventually become prone to damages from wind. However, wind damages sometimes occur when they perhaps should not have – when the winds responsible for the damages weren’t truly “severe,” yet they are nonetheless responsible for considerable loss. In other cases, wind damages may be attributable to more valid winds, but the severity of the loss will be greatly exacerbated by pre-existing conditions or defects in materials and/or workmanship.
Manufacturers generally warrant their products’ performance relative to wind during the early years of the shingles’ lifespan. Donan Engineering is experienced in comparing these performance criteria to real-world failures. Tear strength, sealant strip adhesion, material or assembly defects, etc. are just a few of the items asphalt shingle manufacturers have to properly control to ensure that their shingles perform as they’re intended under real-world wind and weather.
In the realm of asphalt shingles, habits of the installer are perhaps the single greatest asset or shortcoming to a shingle roof’s wind resistance. Therefore, we place great emphasis on how the roofing contractor performed his work from the early stages of preparation through the finished roof installation with respect to published manufacturer and code requirements.
Residential building codes have outlined specific criteria that affect the wind performance for asphalt shingle roofing, and when the code requirements aren’t strictly adhered to, premature failure or unsatisfactory performance is a common result. Contractors should be diligent about their work, and Donan holds a roof’s overall performance in a wind loss directly accountable to the contractor’s ability or inability to adhere to all code and manufacturer requirements.
Wind performance may bear on more than the manufacturer and installer, and we’ve documented several cases where improper material storage can have a detrimental effect on how asphalt shingles perform relative to wind. The signs of improper storage, sometimes called “warehousing,” can be easily overlooked or misinterpreted, so Donan is careful to analyze a wind-damaged roof in search of contributing factors.