Hail Damage: From Structural Scarring to Technological Resilience

Hail’s Devastating Impact

Hail damage to residential structures can manifest as scarring reminiscent of shotgun blasts, particularly following severe storm events. Andrew Shick, CEO of Illinois-based Roofing USA, witnessed such destruction firsthand during a visit to a western Illinois farm complex, where 3-inch hailstones pockmarked even robust metal roofs. “It was extraordinary,” he recalls. “There were baseball-sized holes in the lawn—I had never observed such damage previously.”

Shick attributes the perceived worsening of hailstorms to changing meteorological patterns. The escalating repair costs, compounded by inflation, have led insurers to adjust policies, imposing higher deductibles on hail-damaged properties. “Many homeowners remain unaware of these policy changes until hail strikes their roof,” Shick notes.

Economic and Climatic Context

Hail damage has emerged as a costlier natural hazard in the U.S. In 2024, hail-related expenses exceeded the combined costs of hurricanes and floods, reaching an estimated $40 billion—well into the tens of billions. A decade prior, annual hail damage costs were less than $1 billion, according to Tanya Brown-Giammanco, director of disaster and failure studies at the National Institute of Standards and Technology (NIST), a nonregulatory agency focused on product standards.

Compounding this, population growth in hail-prone regions (e.g., the Central U.S.) amplifies vulnerability. While severe hailstorms appear to have increased in frequency, the link between climate change and hail remains uncertain. Hail forms when thunderstorm updrafts lift raindrops into frigid upper regions, where they freeze and accumulate moisture, eventually falling as stones too heavy for atmospheric support. Rising atmospheric temperatures could either reduce hail frequency (by promoting melt) or intensify larger, more destructive hailstones in specific areas, depending on complex interactions of air currents and moisture.

Researching Hail: Unraveling Nature’s “Meteorological Bombs”

Becky Adams-Selin, principal scientist at Atmospheric and Environmental Research, leads the Integrated Cloud and Hail Impact Project (ICECHIP), a multi-organization initiative studying hail in natural conditions. During field campaigns across the Central Plains and Front Range, her team documented nearly 20 hailstorms, collecting thousands of samples—including a 364.5-gram, 6-inch oblong behemoth that fell from a storm that had earlier produced only pea-sized hail.

A major challenge lies in forecasting: scientists lack precise understanding of hail descent velocities and tumbling behavior, making 2-inch hail predictions beyond 24 hours elusive. Weather radar struggles to distinguish large hailstones, leaving homeowners uncertain of impending damage (e.g., 2-inch vs. 5-inch diameter).

Hail-Resistant Roofing: Testing and Certification

To mitigate risk, companies market hail-resistant roofing products, and insurers increasingly require certifications. Forensic engineering firm Haag Technologies tests materials by firing spherical ice projectiles (up to 2 inches in diameter) via pneumatic cannons at nearly 90 mph. For larger stones, testing involves 4-inch ice balls, which can reveal dents without fracturing.

Certification classes (Class 1 to 4) exist, with Class 4 denoting resistance to 2-inch hailstones under lab conditions. However, real-world hailstones often exceed 2 inches, and lab tests fail to capture their irregular shapes. Metal roofs with gravel-like exteriors, for example, may mask dents but remain expensive. Brown-Giammanco suggests higher certification classes (e.g., Class 5+) could better reflect real-world resilience, though costs may limit adoption.

Forensic Science and Insurance: Navigating Liability

Forensic analysis is critical for insurance claims, where stakeholders often dispute fault. Haag’s impartial testing determines if damage stems from hail, wear-and-tear, or other causes. “Our goal is scientific accuracy, not favoring any party,” notes Smith of Haag.

Adams-Selin’s ongoing research aims to address gaps: 3D-printing plastic replicas of real hailstones and deploying them via drones to measure terminal velocity, using large stadiums to avoid harm. This data will refine models for forecasting and hail mitigation, ensuring homes and infrastructure can better withstand nature’s meteorological onslaught.

Conclusion

Hail’s economic and structural toll underscores the urgency for improved forecasting, resilient materials, and transparent certification. As researchers and industry collaborate, innovations like Adams-Selin’s 3D-printing project promise to transform our ability to predict and protect against these destructive events, ensuring homeowners can better defend their properties against the “shotgun blasts” of the sky.