CLASS 3 & 4 IMPACT RATED ROOF
An impact-resistant roof sounds really great, right? Who wouldn’t want a roof that can withstand a strong storm of hail and wind? It would require fewer repairs and last longer. Well the insurance companies really liked the idea too. They liked the idea so much they decided to pass on savings to consumers who installed them. But first, the roof needed a standardized test and rating system. And that’s where UL stepped in to assist.
Underwriters Laboratories (UL) is a not-for-profit independent testing organization that was founded in 1894. UL provides the knowledge and expertise to help consumers make informed decisions on products that affect their daily lives. UL developed a test to rate the strength of roofing materials. This test is called the UL 2218 Impact Rating.
The test uses steel balls ranging from 1.25 inches to 2.0 inches in diameter. The steel balls are dropped from heights of 12 feet for the 1.25 inch ball to 20 feet for the 2 inch ball. The test roof is struck twice in the same spot for each size steel ball.
To meet the acceptance criteria of UL 2218, the roofing material, back surface and underneath layers must show no evidence of tearing, fracturing, cracking, splitting, rupture, crazing or other evidence of opening of the roof covering layer. Based on how the roofing material performs in the test, it will be classified as Class 1, 2, 3 or 4.
Class 3 roof is earned if the sample does not crack when hit twice in the same spot by a 1.75 inch diameter steel ball. Class 4 roof is earned if the sample does not crack when hit twice in the same spot by a 2 inch diameter steel ball. Roofs with Class 3 or 4 rating can be eligible for insurance discounts to consumers who install the materials on their roof.