While there is no such things as a completely hail-proof roof, certain types of shingles are certainly more resistant to impact than others. Extremely large hail stones can damage anything, they can even pass through roofs, damaging not only the roof surface, but the deeper layers, such as the roof decking as well, but the higher the impact-resistance rating awarded to a specific variety of shingles, the stronger the material can stand in front of severe hail storms. If you are looking for shingles to install on your roof in a hail-prone area, here are a few details about the testing process and about the resistance offered by the different types of shingles available today.
The Testing Methods Used for Assessing Resistance Levels
Roofers in Lincoln tell us that all shingle products available on the market come with a document that contains the product specifications. The details you can find in the document include not only product weight and size, color, material type, composition and the number of layers that make up the shingles, but also various rating, including the product’s impact-resistance class. Currently, shingles are classified into four resistance categories, Class 1 being the lowest and Class 4 the highest, the ratings being given based on impact testing.
Shingles rated Class 1 have passed tests that involved dropping 1-1/4” steel balls from a height of 12 feet onto their surface – only products that survive the impact two times without any surface deterioration can pass. The products rated Class 2 are tested using the same method and are expected to deliver the same performance, but the steel balls dropped are 1-1/2” large and they are also dropped from higher up, the height used for the testing being 15 feet. Class 3 shingles undergo testing with even larger, 1-3/4” balls dropped from 17 feet, while Class 4 shingles need to be able to withstand the impact caused by steel balls that are 2” large or larger, dropped from the height of 20 feet. While the shingles included in Classes 1-3 are inspected only with the naked eye, Class 4 shingles undergo inspection through a magnifying lens to make sure that they can withstand the impact without sustaining any damage.
Other Aspects to Bear in Mind When Picking Your Shingles
Shingles roofs are most commonly associated with roofs that use asphalt shingles, but you must be aware that shingles today are available in many different varieties, including plastic, resin and metal alloys, such as alloys based on aluminum or copper. As all shingles included into an impact-resistance class offer the same level of resistance to impact, when you choose the products for your new roof, you will need to take into consideration other aspects as well:
- Costs – asphalt shingles are the cheapest option, followed by plastic, while metal is always a more expensive solution;
- Thermal performance – shingles also come with an R-rating, the measurement of their capacity to reflect heat. The higher the rating, the more efficient the product in terms of maintaining temperatures in the building;
- Appearance – most shingle types come in a wide array of styles and colors, so take your time to find the best fit for your building.