Class 4, Impact-Resistant Roofing Shingles

If you’re one of the millions of American homeowners who live in an area where intense storms frequently occur, you're likely concerned about roof damage due to hail, airborne debris, and high winds.

But did you know that your choice of roofing shingles plays a critical role in preserving the integrity of your roofing system during severe weather? Impact resistant shingles can offer advanced protection from hail and wind-blown debris.

One of the highest ratings possible for impact-resistant shingles is Class 4. Learn why Class 4 roofing shingles may be worth the upfront investment and discover what goes into creating durable, impact resistant shingles.

What Are Impact-Resistant Shingles?

Roofing shingles labeled as impact-resistant are typically evaluated using one of the standardized industry tests such as UL 2218 and/or FM 4473. These tests use different methods to evaluate the shingles performance and ultimately those that pass are given a class rating system (typically Class 1 – Class 4), with a Class 4 rating being one of the industry's highest for impact.

What Makes a Shingle Impact-Resistant?

Often, impact resistant shingles can have a unique composition and design, making them more durable and resilient.

Impact-resistant shingles may also be known as:

• High impact shingles
• Hail resistant shingles
• Class rated shingles

Why Choose Class 4 Impact-Resistant Roofing Shingles

Every year, thousands of homeowners across the country suffer costly damage to their roofs during hailstorms and other extreme weather events. According to the National Oceanic and Atmospheric Administration (NOAA) Severe Storms database, 4,436 major hail events occurred in the U.S. in 2022, and these storms caused billions of dollars in damage. One insurer alone, State Farm, reported paying out more than $3.5 billion in claims related to hail damage in 2022, a 1 billion dollar increase from the prior year.

Read next: How Do I Know If I Have Roof Hail Damage?

Certain parts of the U.S. are more hail-prone than others. According to the Insurance Information Institute, the five worst states for major hail events in 2022 were:

• Texas, with 458 hailstorms
• Nebraska, with 399 hailstorms
• Minnesota, with 387 hailstorms
• Kansas, with 289 hailstorms
• South Dakota, with 275 hailstorms

If you live in a hail-prone region of the country or an area where frequent severe weather events put your roof at higher risk for damage, you’ll want to consider the potential benefits of Class 4 rated roofing shingles when comparing costs.

Advantages of Class 4 Roofing Shingles

Class 4 roofing shingles are a premium shingle product and may cost more than standard, non-impact resistant shingles. However, due to the beneficial qualities of these high impact shingles, the initial expense may be worthwhile if you live in a region that frequently experiences hail and windstorms.

Class 4 impact-resistant shingles may:

• Eliminate the need for, or reduce the frequency of, roof repairs. Enhanced protection can mean less damage and potentially fewer unexpected repair expenses.
• Extend the lifespan of your roof. Your shingles are your roof’s first line of defense. A roof with intact, undamaged shingles is better protected season after season.
• Be required to meet local building codes: Due to the frequency of hailstorms, some regional and local governments have established code requirements for Class 3 or 4 rated impact resistant shingles, especially for new installations.
• You may save you money on homeowner’s insurance and premiums. Many insurance companies offer discounts for homeowners who use Class 4-rated shingles. Contact your insurance provider to learn more.
  

Impact-Resistant Shingles: Strength and Durability by Design

Non-impact resistant roofing shingles may be more easily damaged when struck by hail or other debris during a storm.

Therefore, industry-leading roofing manufacturers have engineered asphalt shingles that can help withstand greater impacts and potentially reduce the amount of roof damage caused by storms and hail. Thanks to advancements in shingle design and construction, homeowners can have more protection from hail events and less risk of a costly roof damage claim.

Impact-resistant shingles are commonly engineered in two ways:

1. A reinforcing, polymer-based mesh is added to the back of a standard asphalt shingle. This mesh is embedded into the asphalt to strengthen the shingle and help reduce cracking when impacted by a hailstone or other debris.
2. Rubber-like polymers, such as SBS (styrene-butadiene-styrene), can also be added to the asphalt composition to make a shingle more impact-resistant. Integrating the SBS polymer blend with the asphalt produces a rubberizing effect, creating a shingle that is more flexible than standard shingles and more capable of recovering from hail impact.

How Do Roofing Shingles Qualify for a UL 2218 Class 4 Rating?

Back in the mid-1990s, after a series of catastrophic hailstorms across the U.S., the roofing industry developed a test to evaluate their products’ resistance to impact. This standardized test, also known as the Underwriters Laboratory 2218 (UL 2218), is nicknamed “the steel ball test.” This test is now one of the most common used to test and rate the impact resistance of asphalt shingles. Based on the results of this test, UL assigns one of four ratings to a shingle, with Class 4 being the highest possible rating.

During this testing method, a steel ball is dropped from a specified height onto an installed roofing shingle several times. The shingle is then turned over and inspected for any breaks or cracks that could potentially allow water to leak through.

To receive a Class 4 rating, a roofing shingle must withstand having a 2-inch steel ball dropped multiple times from a height of 20 feet. To give you an idea of how strong the shingle must be — if this same test is repeated on a 4-inch concrete paver, the force of the steel ball could crack the paver in half.

While Class 4 is the highest rating for impact resistance, there are also lower ratings a shingle can receive, such as Class 3 and Class 2. The difference between the ratings is that Class 3 shingles withstand a smaller steel ball dropped from a lower height, and likewise for Class 2.

Impact-Resistant Shingles FAQs

Q: Are impact-resistant shingles worth the extra cost?

A: When considering which type of shingles to purchase, carefully weigh the long-term benefits of Class 4 shingles vs. the extra expense of a premium product. Don’t forget to factor insurance discounts, local building regulations and your region’s risk of severe weather into your calculations.

Q: What are examples of an impact-resistant roof?

A: Choosing Class 4 rated shingles designed specifically for impact resistant can improve your roof’s likeliness to withstand wind debris and hailstorms.

Owens Corning Roofing offers several asphalt shingles with a Class 4 rating for impact resistance:

• TruDefinition® Duration FLEX®: These SBS modified asphalt shingles. Are made with a proprietary blend of SBS polymer modified asphalt. The rubberizing effect of the uniquely blended SBS modified asphalt makes the shingle pliable and gives them greater flexibility and enhanced durability and toughness, especially under intense storm conditions.
• TruDefinition® Duration STORM®: Backed with a polymer-based mesh, these shingles are designed to perform better against storms and resist cracking upon impact.
• ImpactRidge® Hip and Ridge Shingles: These SBS, polymer modified hip and ridge shingles are rated Class 4 and pair with both Duration FLEX® and Duration STORM®.

Both TruDefinition Duration FLEX® and TruDefinition Duration STORM® feature our patented SureNail® Technology, which helps prevent nail blow-through and pull-through.

Q: How do I know if my roof is impact resistant?

A: If you’re not sure what roofing shingles were used on your roof, schedule an inspection with a professional roofing contractor. Not only will they be able to tell you if you have hail resistant shingles, but they can also report on the condition of your current shingles and offer maintenance and repair advice.

Q: What is a Class 4 impact-resistant roof?

A: To be considered a Class 4 impact-resistant roof, the roofing surface often must be covered in asphalt shingles or metal panels that have received a Class 4 rating using the UL 2218 or FM 4473 test. You should be able to find the impact rating on the packaging or the manufacturer’s website.

Q: Do I need anything else to make sure that my roof is Class 4 Impact-Resistant?

A: Some insurance providers require that your shingles and your hip and ridge shingles are rated Class 4. Some also require that you install off-ridge vents. Check with your insurance provider to understand all the requirements necessary for your home to qualify for any Class 4 impact resistance related discounts on your insurance premiums.

Q: Are Class 4 Roofing Shingles More Wind Resistant?

A: Class 4 roofing shingles do not necessarily feature a higher wind resistance. Wind ratings are a separate classification. People often talk about Class 4 roofing shingles and wind resistance together because high winds may cause debris to go airborne, impacting roofs and causing damage.

How to Find Class 4, Impact-Resistant Shingles

Browse our roofing shingles to find which Owens Corning® Class 4 impact-resistant roofing shingles are available in your area.

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