What is UL2218?

UL2218 is a professional technical standard specifically designed to evaluate the impact resistance of roofing materials. It is used to determine the ability of these materials to withstand various levels of hailstones impacting at different velocities.

Evaluated Impact Levels

UL2218 categorizes four levels of impact resistance, each representing a different size of simulated hailstone and corresponding kinetic energy:

Class 1: Simulates a hailstone with a diameter of 1.25 inches and with an impact energy equivalent to a free-falling object from a height of 12 feet.

Class 2: Simulates a hailstone with a diameter of 1.5 inches and with an impact energy equivalent to a free-falling object from a height of 15 feet.

Class 3: Simulates a hailstone with a diameter of 1.75 inches and with an impact energy equivalent to a free-falling object from a height of 17 feet.

Class 4: Simulates a hailstone with a diameter of 2 inches and with an impact energy equivalent to a free-falling object from a height of 20 feet.

Test Procedures

To assess the impact resistance, the test involves dropping steel balls of specific sizes onto the roofing material samples. The material's performance is then evaluated based on any visible damage such as cracks, splits, or punctures. The tests are conducted by trained technicians using specialized equipment and following strict protocols.

The roofing materials may be given a rating of Class 1 through 4, indicating their ability to withstand impact. The higher the assigned class, the greater the material's resistance to hail damage.

Importance of UL2218 Certification

UL2218 certification is essential for roofing manufacturers as it provides credibility and reliability to their products. It allows consumers, architects, insurers, and building code officials to have confidence in the tested product's ability to resist hailstone impacts.

For insurance purposes, many providers require roofing materials to meet specific UL2218 classes to qualify for coverage against hail damage. Having a UL2218 rating can potentially lead to lower insurance premiums for homeowners.