In 2017, Texas, USA, reported more than 700 hailstorms with stones greater than 1 inch in diameter. In December 2018, Australia was hit with its worst hailstorm in 20 years. A July 2019 hailstorm in Europe caused US$7M in damage to a manufacturing facility insured by AFM. This worldwide hazard has caused US$1.3B in reported loss to AFM and FM Global clients during the past 10 years.
As the losses have increased in recent years, so have our assessment and mitigation efforts. Since 2014, FM Global has released several new hail protection guidelines. FM Global made its US Hail Map available on AFM Online in 2018 and on public websites in 2019. The hail hazard for other areas of the world is currently being evaluated and additional maps will be released when available.
The map identifies hail hazards based on the frequency and severity of hailstorms. Considering the hail size and frequency together is essential for quantifying the hail hazard, which is the first step toward more cost-effective loss prevention solutions. The map has three zones: moderate, severe and very severe (VSH). Knowing which zone a property is in can help clients to make informed decisions on the products that can be used to limit loss.
Assistance to evaluate hail hazard
Clients and brokers can work with AFM account teams to evaluate a roof's exposure to hail damage. AFM engineers consider the hail zone, condition of the roof, age of the roof and the sensitivity of the occupancy to recommend protection solutions. This guidance is based on FM Global Property Loss Prevention Data Sheet 1-34, Hail Damage. (Register here to receive data sheets.)
Here are a few practical pieces of advice based on our loss history and our engineering research:
- Properly maintain the roof and replace it when needed. Roofs that are in poor condition or not properly rated for the hail area are more susceptible to hail damage. If vulnerabilities such as cracks and blisters are visible, then replacement is recommended. Single- and multi-ply roofs have an average life expectancy of 14 to 18 years.
- It's a much smoother process and less disruptive to the business to replace an old roof than to scramble to find a reputable roofing contractor after a major hailstorm blows through and causes damage. This is most critical in the VSH area where most roofs are not rated for the VSH hazard.
- Involve AFM in re-roofing projects to make sure that the roof's hail rating matches the severity of the hail zone. Roofing products rated for use in moderate, severe or very severe hail zones can be found in RoofNav, an online tool that provides the most up-to-date roofing products and assemblies.
- Use skylights with the appropriate hail rating (and hail guards in the VSH area) along with hail guards for the condenser coils on HVAC equipment.
- Report damage right away. In many cases, the longer damage is left unrepaired, the worse it gets, resulting in a more difficult and costly fix. For example, rain entering a building with a hail-damaged roof can significantly increase damage.