Wind Creased Shingles: Identification and Significance

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A crease across a shingle tab can mean very different things depending on where it sits and how it formed. Wind creasing occurs when sustained or gusting wind lifts a shingle tab away from the roof deck and then presses it back down, sometimes repeatedly, bending the shingle along a line roughly parallel to the eave. Because asphalt shingles are somewhat flexible in warm conditions and considerably less so in cold weather, the same wind event can produce a visible crease on one roof and none at all on another, depending largely on the shingle’s temperature and age at the time of the wind exposure.

Identifying a wind crease involves looking closely at the shingle mat itself, not just the surface granules. A pronounced crease often shows a fracture line in the fiberglass or organic mat beneath the asphalt coating, visible when the tab is gently lifted, and that fracture is what distinguishes functional wind damage from a cosmetic bend that has not actually compromised the shingle’s structure. Sealant strip condition is examined alongside the crease itself, since a shingle that has been repeatedly lifted by wind often shows a broken or failed seal along the adhesive strip that normally bonds it to the course below.

Wind creasing is distinguished from other causes of similar-looking marks, including manufacturing defects, improper installation such as inadequate fastening, and simple aging of the shingle material. Industry testing standards such as ASTM D3161 and ASTM D7158 establish wind resistance test methods used to rate shingle products, and inspectors sometimes reference the shingle’s rated wind resistance class in the context of evaluating whether a documented wind speed at the property was consistent with the type of damage observed, though a rating alone does not determine the cause of any specific crease found during inspection.

The significance of a confirmed wind crease lies in what it indicates about the shingle’s remaining performance. A creased shingle with a broken mat and failed seal is generally considered to have reduced wind and water resistance going forward, even though it may still be physically attached to the roof and show no immediate leak. Documenting the location, extent, and pattern of creasing across a roof slope, typically through close-up photographs paired with a diagram noting where creasing was found, supports an accurate scope regardless of which party is reviewing the file.

Shingle architecture affects how creasing shows up on a roof. Three-tab shingles, being a single uniform layer, tend to crease along the full width of the tab in a fairly consistent way, while laminated or architectural shingles, built from two bonded layers of asphalt, can crease in the upper layer without necessarily fracturing the lower layer beneath it, or vice versa. Inspecting both layers where they can be separated, rather than assuming the surface layer alone tells the full story, is part of a careful evaluation on architectural shingle roofs, since the lamination itself changes how bending stress moves through the material compared to a single-layer product.

General education only: the appraisal process described here can vary by state and policy language, and nothing in this article is legal advice.

Russ Lis is a working property insurance appraiser and umpire based in Minnesota, serving clients nationwide. Contact Appraisal Resolution.