Hail Damage 101
During the course of an average year, hail causes more than $1.6 billion worth of damage to residential roofs in the United States. Hail storms are most frequent in the Southern and Central Plains states where warm, moist air off of the Gulf of Mexico and cold, dry air from Canada collide. The combination of the two different air masses spawn violent thunderstorms.
Hail is created when frozen water drops are lifted in turbulent wind regimes during thunderstorms. As the frozen water is driven to the earth at speeds up to 90 mph, it has the ability to increase in size and form a hail stone. Hail stones can vary in size from pea sized (1/4-inch diameter, minimal roof damage), quarter sized (1-inch diameter, moderate roof damage), golf-ball sized (1.5-inch diameter, severe roof damage) or even larger, causing catastrophic damage.
The two main types of damage caused by a hailstorm to your composition roof are granule loss (exposing the underlying mat) and rupturing the mat of the shingle. Loss of granules will shorten the life expectancy of the roof. Since the granules have been removed by the hail stones, the matting is now exposed to the elements. The UV rays from the sun over time will cause the mat to crack, adversely affecting the water-shedding ability the roof previously had. Rupturing of the mat is the more severe of the two types of hail damage. This is caused by larger hail stones impacting the shingle. When a shingle’s mat has been ruptured, the granules are gone and cracking or a hole is visible in places where the hail impacted the shingle. This greatly affects the shingle’s intended purpose of shedding water.
Any time a shingle loses its water-shedding ability, whether from granule loss or rupturing of the mat, water will start to deteriorate your roofing system. Once the water reaches the roof fasteners, causing corrosion of the butted joints in the roof decking, water will be permitted to enter the building.
As soon as possible after any storm, have Exterior Building Solutions inspect your roof free of charge. You can seldom see roof damage caused by hail from the ground. Most people not trained in the detection of hail damage are unable to correctly identify hail damage even while on the roof.