Westlake Royal Building Products^™ (Westlake Royal), a Westlake company, announced today that Unified Steel^® Stone Coated Roofing has received the Very Severe Hail (VSH) rating in accordance with ANSI FM4473 American National Standard for Impact Resistance Testing of Rigid Roofing Materials by Impacting with Freezer Ice Balls. The durable, lightweight roofing system, which benefits from the structural strength of steel, is the first stone coated steel roofing product on the market in the U.S. which has obtained the VSH rating.

“The roof is often the first point of contact for the hailstorms that damage homes every year,” says Steve Booz, Vice President, marketing, Westlake Royal Building Products. “Hailstorms are increasing the repair and insurance costs incurred by homeowners and, as a result, roofing materials that have been tested to the most stringent in hail resistance standards are in high demand.”

NOAA reported 6,962 hail events in the United States in 2023 alone, an increase from the 4,436 hail events recorded the year prior.¹ As of April 22, 2024, NOAA had reported 1,182 severe hail events in the U.S.²  Hailstorms are now responsible for billions in damages each year in the U.S.³ As a result, insurers are reporting large losses. In 2023, State Farm paid 27,300 claims for hail damage to homes and businesses, up from 23,200 in 2022. The company’s payouts for 2023 totaled $6.1 billion, more than the previous two years combined.⁴

In order to qualify as an FM4473 certified roofing product, steep slope roofing materials must possess adequate physical properties to demonstrate hail impact resistance as it relates to hailstorms. Minimum accepted performance is Class 2 nominal 1.5-inch (38.1 mm) diameter ice ball. Classifications also include Class 3 nominal, or 1.75-inch (44.5 mm) sized ice ball, and Class 4 nominal, or 2.0-inch (50.8 mm) sized ice ball. Certification for these ratings is contingent on two successful test specimens meeting the acceptable criteria to qualify for the given classification. 

For the Very Severe Hail (VSH) rating, 2.0-inch (50.8 mm) ice balls are also used, however they are weathered prior to testing. Additionally, three successful test specimens must meet the criteria. During both Class 4 and VSH testing, a 2-inch ice ball is shot at the test subject at different speeds, producing a set kinetic energy at impact. Class 4 shoots the ball to target a kinetic energy of 26.8-foot pounds of force, while the VSH Classification doubles that to 53-foot pounds of force. To double the force in Unified Steel’s qualifying testing for VSH, the speed of the ice ball was increased from about 55 mph to approximately 110 mph.

Unified Steel has achieved both the Class 4 and VSH classifications.

“By meeting the VSH classification outlined by FM Approval and listed in QAI CER 1008, Unified Steel Stone Coated Roofing has demonstrated the ability to help protect the structure from further damage caused by severe hail impacts,” says Eric Miller, Vice President, sales, for Westlake Royal Building Products roofing solutions. “The VSH designation also sets Unified Steel apart from most steep slope roofing products.”

The product is offered with a 50-year limited and fully transferable warranty.⁵ Explore Unified Steel here. For information on the company’s full suite of concrete, composite, clay, steel, and components roofing options, visit Westlake Royal Roofing Solutions.

1. Facts + Statistics: Hail, Insurance Information Institute, February 8, 2024, https://www.iii.org/fact-statistic/facts-statistics-hail

2. 2024 Annual Preliminary Report Summary, NOAA / National Weather Service Storm Prediction Center, April 22, 2024, https://www.spc.noaa.gov/climo/summary/

3. The Rise of Giant Hailstones, BBC, April 19, 2024, https://www.bbc.com/reel/video/p0hrvjjx/the-rise-of-the-giant-hailstones

4. Insurers Report Rising Hail Damage Claims, New York Times, March 22, 2024, https://www.nytimes.com/2024/03/22/your-money/insurers-report-rising-hail-damage-claims.html

5. For product warranty details, visit https://westlakeroyalroofing.com/resources/steel/warranties/. The warranty found there is the sole warranty applicable to Unified Steel.