According to asphalt shingle roof contractors, asphalt shingles are one of the most popular types of roofing installed today due to their durability and affordability.
When designing products to be installed by asphalt shingle roof services, roofing materials manufacturers put their products through multiple quality tests, one of them being an impact test.
Impact testing ensures that the shingles installed by asphalt roof services will withstand impacts up to the rating of that product.
For homeowners in parts of Texas that are prone to hailstorms, impact resistance is a very desirable quality.
How Is Impact Testing Done on Shingles?
There are two main tests used to determine the impact resistance of specific products installed by asphalt shingle roof contractors.
Those are the Underwriters Lab (UL) standard 2218 Impact Resistance test and the Insurance Institute for Business and Home Safety (IIBHS) Impact Resistance Test.
What is Involved With the UL 2218 Impact Resistance Test?
The UL 2218 test, also called the steel ball test, is done by dropping various-sized steel balls from a distance of between 12 and 20 feet onto the roofing material to see how it is affected.
The test is run by dropping the balls onto a fully installed test roof on various parts of the roof, then deconstructing the roof afterward to examine it.
Specifically, the backs of the shingles are inspected to look for any cracks and tears caused by the impacts of the steel balls.
Products are then rated according to their impact resistance and made available to asphalt roof services to install for their customers.
What Is Involved With The IIBHS Impact Resistance Test?
The IIIBS test is done under similar conditions on a test roofing deck but using a slightly different method.
According to asphalt shingle roof services, this test involves shooting various sizes of man-made hailstones of various hardness at the test deck, then analyzing the impacts afterward.
This test evaluates not just the cracks and tears that can occur due to impacts, but also details like granule loss and surface dents.
Based on the results of those tests, a variety of grades on the different measurements is given.
What Do the End Results Mean?
While both tests assess impact resistance in similar ways and assign impact-resistance ratings to the products used by asphalt shingle roof contractors, they are also somewhat different in their end results.
The criteria for which each test passes or fails a product is different.
While the IIIBS test is more in-depth and stringent and offers a variety of grades, it is also more complex to determine which is the best product.
On the other hand, the UL 2218 test looks at only one factor and gives a clear pass/fail rating.
When purchasing shingles from asphalt roof services, consumers should be aware of these two methods and how they are interpreted in the impact-resistance ratings of different shingles.