What Hail Damage Looks Like on a Roof: Shingles, Wood, Tile and Metal

On asphalt shingles, hail damage looks like a scatter of spots where hail knocked the granules off and exposed the black asphalt underneath, soft “bruises” that give when pressed, and cracks, punctures or torn edges. The Insurance Institute for Business & Home Safety (IBHS) lists a “random pattern of impact marks on shingles” and “soft spots you can feel when pressing on the shingle” among the main signs. Wood shingles split, tile cracks or shatters, and metal dents. From the ground you mostly see evidence around the roof, such as dented gutters and air-conditioner fins; bruises are found by hand, up close, by a roofer. Not every mark counts: in Haag Engineering’s papers, damage means a mark that cuts the roof’s ability to shed water or shortens its expected life.

How a hailstone leaves its mark

In a 2014 claims study, IBHS researchers wrote that hailstorms “primarily affect the roof system,” especially when there is little wind and stones fall vertically; with strong wind, hailstones “may be propelled at an angle,” doing more damage to walls and windows, and roof slopes that face the wind often take more damage. Haag’s engineers add that “the windward slope typically sustains the most concentrated and direct hail impacts.” NOAA’s National Severe Storms Laboratory notes that wind-blown hail can also wreck siding and break windows.

Mark size follows stone size, loosely: Haag cites earlier work finding that bruises and punctures in poorly supported asphalt shingles “approached the same diameter as the hailstone,” while dents in wood were about half. Size thresholds by material are on the hail size chart.

Hail damage signs by roof type

Asphalt. IBHS says ridge caps “are especially vulnerable.” Haag adds that shingles with little support underneath, “especially along ridges, rakes, eaves, and valleys,” take damage more easily, and that shingle edges chip and break. In a 2013 IBHS demonstration with 1- to 2-inch hail, most hits on new 3-tab shingles were functional damage; most on new impact-resistant shingles were cosmetic.

Wood. This Old House says wood shake roofs “can dent, crack, or split from heavy hail.” In Haag’s lab tests, ice balls fired at cedar shingles weathered about 11 years split them along the grain into hairline fractures that “could be closed tight.”

Tile. Haag’s tile study defined concrete tile damage as “a fracture in the material,” usually several irregular cracks spreading from the point of impact; fractures above the headlap, where tiles overlap, were functional damage. In Haag’s lab test on Spanish clay S-tiles, 1.25-inch ice balls caused no fractures; at 1.5 inches “all tile corners broke,” while hits in the middle of the tiles did not. The lab ice was “harder and denser than natural hailstones.”

Metal. In the IBHS demonstration, where “all products on the building were new and recently installed,” metal laid over 3-tab shingles dented “larger and deeper” than metal on a plain deck. How policies treat dents is on the metal roof page.

What you can see from the ground, and what only a roofer finds

Hail leaves its clearest record on soft things around the house. IBHS advises looking for “spatter marks or impact dents” on air conditioners, gutters, downspouts and patio furniture, because “collateral damage confirms a hail event occurred.” Haag found dented AC fins “excellent indicators of hailstone size and direction/angle of hailfall,” and on weathered wood fences hail left scuffs like “a bug smear on a vehicle windshield.”

Our summary of the sources above; “often”, “sometimes” and “rarely” are our rough guide, not figures from the sources.

This Old House contractor Tom Silva recommends checking a roof “from the ground using binoculars” for cracked or curling shingles. Stay on the ground or at a window; pressing on shingles is a job for a licensed roofer. The Texas Department of Insurance adds that skylights, roof vents and turbines are “vulnerable to high winds and hail.”

Look-alikes: marks that aren’t hail

Inspectors often mistake other marks for hail, Haag’s engineers wrote:

• Blisters. Small bubbles that rupture and leave steep-sided pits. Haag says they come from poor-quality asphalt combined with heat, are “usually 1/4 in. (.6 cm) in diameter or less,” and are not caused by hail. More on hail damage vs blistering.
• Normal granule loss. IBHS lists granule loss along shingle edges, “uniform wear or discoloration,” manufacturer defects and marks from installation or tools, and notes that “granules can be knocked off by heavy rain.”
• Aging. Splitting, cupping, clawing, crazing and flaking come with age; noticing them after a storm “does not mean they were created or aggravated by the storm,” Haag writes.
• Adhesive spots. Adhesive can drip onto shingles, leaving what Haag calls “a round, dark spot that can be mistaken by some as hail damage”; shingles stuck together can also lose a round patch of granules when pulled apart.
• Foot traffic. Walking on hot, soft shingles pushes granules aside (Haag calls it marring), and walking on tile can break it.
• Tile corner cracks. Curved cracks at the lower right corners of concrete tiles can come from tight installation, foot traffic or manufacturing; “algae or dirt in the fractures” usually shows they are old, Haag says.
• Tool marks. These sit in lines or groups near shingle centers, Haag found; hail leaves a random spread.

New damage or old?

On asphalt, Haag writes, “recently exposed asphalt appears black or unweathered,” while asphalt exposed for several months oxidizes to grey. Dents in metal never go away, so Haag warns that some may date from earlier storms. Write down the storm date and time so a roofer can tie the marks to that storm.

Cosmetic or functional: the line that matters

Haag defines functional hail damage to asphalt shingles as “punctures, tears, or fractures (bruises) in the shingle mats,” and its 2002 paper also counts “the displacement of granules to visibly expose the underlying bitumen.” In a 10-year test, Haag wire-brushed granules off new three-tab fiberglass shingles and left them outdoors in Dallas; those with about 70% of their granules removed still shed water, and Haag concluded that shingles losing some granules in a storm “are not considered damaged as long as the shingles remain covered with granules.” Haag’s 2004 paper calls granule loss without exposed asphalt “a controversy”: many shingle makers say granules lost to hail shorten a shingle’s life, while Haag writes that “there are no published scientific studies to validate this statement.” IBHS, for its part, listed as an open research question whether cosmetic marks on shingles lead to further wear.

IBHS’s public summary of a 2019 study of dents in shingles says “small dents resulted in negligible water leakage,” while larger dents leaked much more, and a tear rated close to 1 on a 0–3 severity scale “allowed large amounts of water leakage.” In the 2013 demonstration, IBHS rated the dents on new metal panels “cosmetic in nature.” How your policy treats cosmetic marks is a question for your insurer; see the hail damage roof insurance claim guide. What a roofer checks, slope by slope, is on hail damage roof inspection.

Common questions

Questions to ask your roofer

• Which marks are functional damage (bruises, punctures, tears, splits) and which are cosmetic?
• Which slopes took the most hits, and does that match the storm’s direction?
• Could any of these marks be blisters, wear, foot traffic or an older storm?
• Will you photograph each kind of damage and mark where it is?

To weigh what you saw from the yard, try the step-by-step hail damage check.