How can you tell hail damage from wind damage on a roof?

Hail leaves impacts: dents, tears, and lost granules in a random pattern of strike marks, per IBHS and the Nebraska Department of Insurance. Wind lifts: suction pulls at shingles, and once one tab fails it can rip off others. The adjuster decides the cause.

What is a test square on a roof?

A fixed area of a roof slope where verified hail hits are counted. University of Missouri Extension cites a formula like 10 verified hits per 100 square feet, and notes that standards differ by company.

Is granule loss always hail damage?

No. The Nebraska Department of Insurance says granule loss by itself does not prove hail damage, and IBHS has observed granule loss on aging shingles from everyday weather.

Does lossmap decide whether damage is from hail or wind?

No. lossmap provides aerial imagery and visual documentation. It is not a licensed roof inspection, an engineering report, or an insurance determination. Cause and coverage stay with the adjuster and the carrier.

Hail vs. Wind Roof Damage: How Each Is Documented

The Texas Department of Insurance tells homeowners to ask whether their deductible for wind and hail differs from the one for other damage. On the roof, the two leave different evidence, and the file should show it.

What hail looks like

IBHS, the Insurance Institute for Business & Home Safety, says hail can dent an asphalt shingle, tear it, or knock granules off. Tile may crack or shatter. Metal dents, and IBHS notes there is currently no evidence that dents affect how a metal roof works.

The Nebraska Department of Insurance says hail leaves strike marks of various sizes in a random pattern, with a bruise in the mat. If the damage follows a pattern, it was not hail. Nebraska adds that it generally takes hail about 1¼ inches across to damage heavy composite or wood shake shingles.

What wind looks like

IBHS explains that wind across a roof creates suction that tries to lift the roof cover off. On asphalt shingles the sealant strip resists that pull. Once one tab fails, it can start a cascade, ripping off other shingles and exposing the underlayment. Starter strips at the eaves and rakes resist uplift at the edges. IBHS says after 7 to 10 years sealant is weak enough to significantly reduce wind resistance.

NOAA classifies damaging thunderstorm winds as those over 50 to 60 mph, and the National Weather Service says isolated wind damage is possible when winds are sustained at 40 to 50 mph.

Directional patterns

NOAA says strong surface winds can drive hail at an angle or nearly sideways, tearing up siding and breaking windows. IBHS notes that, depending on the prevailing wind direction, wind blowing up a slope adds to the forces on a shingle. Either way, which sides took the damage matters, so every slope and every elevation belongs in the file.

Look-alikes

Not every mark is storm damage. The Nebraska Department of Insurance lists look-alikes: blisters, curled edges, hairline cracks, algae streaks, manufacturing defects, and hammer marks near ridges. IBHS has watched shingles shed granules, unseal, and curl from everyday weather alone. The Texas Department of Insurance says a carrier will not pay for a new roof just because it is old or worn out.

Test squares and collateral damage

For hail, the count matters. University of Missouri Extension says an insurance company may use a formula, such as 10 verified hail hits per 100 square feet, to decide on a roof replacement, and that companies can have different standards. A marked counting area like that, laid out on each slope, is what adjusters call a test square.

Collateral damage backs up the roof. Nebraska says hail strong enough to damage a roof will also damage nearby cars, wood fences, shutters, and siding, though granule loss alone does not prove hail.

What the adjuster expects in the file

The Texas Department of Insurance tells policyholders to take pictures and video, list the damage, keep damaged items, and prevent more damage. Nebraska suggests a written list of other damaged items and photos of anything repaired before the adjuster arrives. Whether the cause was hail, wind, or age is the adjuster’s and the carrier’s call.

How lossmap flies each

Each type of loss has its own shot list, flown by a vetted FAA Part 107 pilot carrying at least $1,000,000 in liability insurance. Both start with the roof from overhead and four cardinal obliques at the same altitude and angle. After hail, the close passes cover the roof slope by slope, the soft metals, and the elevations. After wind, they look for missing and creased shingles and lifted membrane. Damage photos carry a scale reference, and everything lands in one gallery you can send by link, with a download bundle and the claim number on the order.

See drone roof inspection reports, aerial documentation for insurance claim files, whether insurers accept drone roof photos, and the FAA rules for drone roof inspections.

Sources

Checked October 9, 2026.