What Size Hail Will Damage a Roof?

The size of hail that damages a roof depends on the roofing material, the age of the roof, wind speed during the storm, and the angle of impact. As a general threshold, hailstones 1 inch in diameter (quarter-sized) and larger can cause functional damage to standard asphalt shingles. Soft metals like aluminum gutters and roof vents can dent from hailstones as small as 3/4 inch. The relationship between hail size and damage is not linear, because wind speed, stone density, and material condition all affect the outcome.

Hail Size Reference Chart

Hail is commonly described using everyday objects for size comparison. Here are the standard references used by the National Weather Service and insurance adjusters:

Diameter	Common Comparison	Typical Roof Impact
3/4 inch	Penny	Dents soft metals (vents, gutters). Minor granule displacement on aged shingles.
1 inch	Quarter	Bruises and cracks asphalt shingles. Reliable damage to soft metals. Threshold for most insurance claims.
1.25 inches	Half dollar	Consistent shingle damage across multiple roof slopes. Fractures underlayment on older roofs.
1.5 inches	Ping pong ball	Widespread shingle damage. Cracks clay and concrete tile. Dents aluminum and light-gauge steel roofing.
1.75 inches	Golf ball	Severe damage to all residential roofing types. Punctures aging shingles. Significant metal deformation.
2.5 inches	Tennis ball	Catastrophic damage. Punctures most roofing materials. Breaks wood shakes and slate.

These are general guidelines. The actual damage depends on multiple factors beyond size alone.

Why the Same Hail Size Causes Different Damage

A 1-inch hailstone falling straight down in calm wind hits a roof with less force than the same stone driven by 40 mph wind gusts. Wind increases the kinetic energy of the hailstone, and it also changes the angle of impact. A roof slope facing into the wind receives more severe hits than a sheltered slope. This is why adjusters often find significantly more damage on the windward side of a roof.

Roof age is equally important. A 5-year-old architectural shingle absorbs hail impact differently than a 20-year-old shingle of the same product. Older shingles have less flexible asphalt, thinner granule coverage, and weaker mat integrity. The same hailstone that bruises a new shingle may crack an old one outright.

Temperature also plays a role. Shingles are more brittle in cold weather. A hailstorm during a spring cold front when temperatures drop below 40 degrees Fahrenheit produces more cracking than the same sized hail on a warm summer day when shingles are pliable.

Impact Resistance Ratings Explained

The roofing industry uses UL 2218 to rate shingle impact resistance on a scale from Class 1 to Class 4. The test drops a steel ball onto the shingle from a set height. Class 1 uses a 1.25-inch ball. Class 4 uses a 2-inch ball dropped from 20 feet. The shingle must withstand two hits at the same point without cracking.

Class 4 shingles are specifically engineered for hail-prone regions. They use modified asphalt formulations, SBS (styrene-butadiene-styrene) polymer modifiers, or rubberized compounds that flex on impact instead of cracking. Many insurance carriers offer premium discounts ranging from 10 to 35 percent for Class 4 rated roofs, depending on the state and the carrier.

Standard 3-tab shingles typically rate Class 1 or Class 2. Standard architectural shingles range from Class 1 to Class 3. Only specific product lines marketed as impact-resistant carry the Class 4 rating.

Damage Thresholds by Roofing Material

Asphalt shingles (3-tab): Vulnerable to functional damage starting at 1-inch hail. The single-layer construction and thinner mat crack more easily than laminated products. These shingles represent the lowest impact resistance among common residential materials.

Architectural (laminated) shingles: More resistant than 3-tab due to the multi-layer construction. Standard architectural shingles typically sustain functional damage from hail 1.25 inches and larger. Impact-resistant versions (Class 4) tolerate up to 2-inch hail under test conditions.

Metal roofing: Metal does not crack, but it dents. The damage threshold depends on the gauge (thickness) of the metal. Light-gauge aluminum dents from 3/4-inch hail. Heavy-gauge steel (26-gauge and thicker) resists denting from hail under 1.5 inches in most conditions. Standing seam panels in 24-gauge steel tolerate larger hail than exposed-fastener panels in 29-gauge.

Clay and concrete tile: These materials are brittle and crack from direct hail impact starting at approximately 1.25 inches. Tiles on steeper slopes may deflect glancing hits. Broken tiles require individual replacement, which is simpler than matching shingle batches but demands skilled labor.

Wood shakes: Cedar shakes split from hail impact starting at roughly 1.5 inches. Older, dried-out shakes are more vulnerable. New shakes with higher moisture content absorb impact better.

What This Means for Insurance Claims

Insurance carriers do not approve claims based on hail size alone. The weather report confirming 1.5-inch hail in your zip code supports the claim, but the adjuster's on-roof inspection determines the actual scope. They are looking for functional damage, meaning the roofing material can no longer perform its intended function of shedding water.

Cosmetic damage, like minor granule displacement or shallow metal dents that do not affect waterproofing, may not be covered under policies with cosmetic damage exclusions. This distinction matters most for metal roofs and newer shingle roofs where dents or bruises are present but the material still functions.

When you receive the adjuster's estimate as a PDF and need to verify the scope in Xactimate, tools like CapOut convert that PDF into your Xactimate account in minutes, not hours. You can review every line item the adjuster included and identify what they missed without manually re-keying the estimate.

Related Guides

• What Does Hail Damage Look Like on a Roof?
• How to Tell If Your Roof Has Hail Damage
• Hail Damage Roof Repair Cost
• Hail Damage Roof Insurance Claims Guide