Make The Right Choice
The International Building Code currently does not require the consideration of impact resistance in the selection of roofing materials.
If the maps listed below indicate your area is prone to hail damage, it is important to take that fact into consideration when replacing your roof. While the average lifespan of some roofs is 20 years, roofs in severe hail-prone areas often must be replaced every seven to 10 years, according to insurance industry data. IBHS offers the following guidance to help consumers make the right choices when selecting a roof coverings in hail-prone areas.
Evaluate The Risk
There are approximately 3,000 hailstorms annually in the United States, resulting in average insured losses of $1.6 billion. Determining your hail risk is the first step in deciding if your roof could withstand major damage in a hail storm.
Hailstones can cause significant damage to roofs, windows, siding and more.
An IBHS review of research and testing related to hail damage indicates that there is considerable variation in the impact resistance of different types of roof coverings. Lab tests and field observations indicate that 3-tab asphalt shingles may be damaged by hail as small as 1 in. IBHS created two maps illustrating hail storms in the last decade and in the last 55 years to help identify areas at risk from hail damage.
The roof is your home’s first line of defense against costly natural disasters such as hailstorms. Once the roof fails, it exposes other parts of your home to damage, which can lead to a breakdown of your home. Physical damage from a hailstorm or high winds aren’t the only threats to your roof’s performance; exposure to weather conditions such as extreme cold or heat can also take a toll. To keep your home’s roof in top condition, it’s critical that you routinely inspect it, quickly repair any wear and tear, and replace it when necessary. Below is guidance on the different types of roofs including information on the effects of hail.
Getting the Roof Right
Having the right materials on your roof is key to its performance during a hailstorm. When repairing or replacing a roof, look for roofing materials rated by UL 2218 or FM 4473 as Class 3 or 4. These standards are recognized by any roofer or building materials store and indicates the material has been tested for impact resistance.
Asphalt shingles are a lightweight, low-cost and easy-to-install roofing material. UL 2218 Class 3 and 4 impact resistance is available and should be used in hail-prone regions.
Metal roofs have a long life and are lightweight. UL 2218 Class 4 products rated for impact resistance are available; these are usually not punctured in hailstorms, but they often receive cosmetic damage or dents from hailstorms.
Slate is a very strong roofing material that can meet FM 4473 Class 3 or 4 impact resistance depending on the type of slate. High-quality slate can outlast most other roofing materials.
Tile is a solid, heavyweight, long-lasting product available with FM 4473 Class 3 or 4 impact resistance. It can be more porous than other products if exposed to blowing rain, requiring a high-quality, well-sealed material underneath it.
According to the Institute for Catastrophic Loss Reduction, roof slope can have an impact on the severity of hail damage:
“Roof slope is an important factor when considering damage from hail. A steeply-sloped roof can reduce overall hail damage in two ways. First, if the hail falls in a relatively straight path, a steep roof can limit damage as it is usually direct – and not glancing – impacts from hailstones that cause roof damage in hail storms (steep roofs limit direct hits and increase glancing or ricocheted of hailstones). Second, if the hail falls on an angle, while the part of the roof facing the wind will likely experience damage, the wind-shaded side may get less or no damage, depending on the angle of impact and steepness of the roof.”
– Source: ICLR Protect Your Home from Hail