Are you trying to decide between a class 3 rated shingle and a class 4 rated shingle? Are you wondering if a class 4 shingle is even worth the investment?
I’m sure seeing or hearing a shingle has “class” is confusing enough, but there are also different levels to these ratings. This isn’t just something slapped on a shingle to identify it.
The classification is actually determined by 3rd-party testing. And because of what it tests, a shingle’s class should always be considered when making a decision.
So, what do the shingle classes mean? And what’s the difference between class 3 and class 4 shingles?
For over 35 years, Bill Ragan Roofing has simplified the technical and complex information homeowners need to choose the right roofing material. That’s why I’ll help you understand shingle classifications and the differences between them.
By the end of this article, you’ll have the answers to the following questions:
A shingle’s classification (or class) is the impact-resistance rating for its ability to withstand hail or other impacts. Impact ratings go from 1 to 4, with each class representing the size of hail a shingle can handle without getting damaged.
The classification is determined through Factory Mutual (FM) or Underwriters Laboratories (UL) by testing a shingle's ability to withstand an impact from 20 feet. They do the test the same way, but UL uses steel balls, while FM uses ice balls that are denser and harder than most hailstones.
Shingle Class Ratings |
| Class 1 shingles can withstand steel/ice balls that are 1.25” in diameter. |
| Class 2 shingles can withstand steel/ice balls that are 1.5” in diameter. |
| Class 3 shingles can withstand steel/ice balls that are 1.75” in diameter. |
| Class 4 shingles can withstand steel/ice balls that are 2” in diameter. |
Just know these tests can’t 100% replicate shingle performance due to factors like temperature, shingle age, and impact angle. So, it’s still possible for hail to damage any shingle class if the conditions are right.
The main difference in class 3 and class 4 rated shingles is obviously the impact-resistance rating. While that is the big draw, there are a few other benefits that a class 4 shingle has over a class 3 shingle.
Let's compare class 3 to class 4 shingles on:
A class 3 shingle can handle 1.75” hail, which is still very impact resistant. In many places in the United States, this is strong enough to handle most hail storms.
On the other hand, a class 4 shingle can handle hail up to 2" in diameter. While some class 4 shingles are thicker, many have specialized materials/formulas that make shingles impact-resistant.
One way to make a shingle class 4 is by adding a polymer-modified mesh that holds together instead of splitting when hail or another object hits. However, this can end up weakening with frequent or continuous hail storms.
The most popular way to make a shingle class 4 by is adding a rubber-type polymer (mainly styrene-butadiene-styrene aka SBS), which allows the hail to bounce off the shingles instead of absorbing the impact. But while class 4 is the highest impact rating a shingle can have, class 3 is still very durable.
The impact resistance rating really only has to do with hail resistance. However, class 4 shingles are generally marketed to last longer than class 3 shingles.
Class 4 shingles are stronger simply because they're thicker, have a multi-layer design, a reinforced mat, shingle formula modification, or a combination. But whatever the reason, if you see a class 4 rating, it's generally a longer lasting shingle compared to a class 3 rated shingle.
The United States is getting hammered by hail storms and more extreme weather than ever before. That's why insurance companies offer insurance premium benefits when installing a class 4 rated shingle on your home.
However, this heavily depends on your area and the insurance company. In fact, insurance companies are doing everything they can to get out of roofing coverage right now.
So, not having to worry about hail damage and dealing with insurance company is just another great reason to invest in a class 4 shingle.
Impact-resistant shingles are considered performance shingles, and some even only come in designer or luxury lines. Because of this, most class 4 shingles are more expensive than class 3 or other traditional asphalt shingles.
Upgrading from a class 3 to a class 4 architectural asphalt shingle costs around 10% to 15%. However, some luxury shingles are class 3.
So, a class 3 luxury shingle compared to a class 4 architectural shingle is the one exception where class 3 shingle costs more. Even if they have the same rating, a luxury shingle will be around double the cost of architectural shingles.
Unfortunately, pricing heavily depends on the type of shingle, manufacturer, and your area. So, I can’t be exact about the cost differences.
The roofing industry is replacing roofs at a record pace right now as damaging storms become more frequent in the United States. In my opinion, Class 4 impact-resistant shingles are worth the initial high investment.
As I said, some insurance companies offer policy discounts for Class 4 shingles, and the changes coming to the insurance industry make it more important than ever to have a roof with strong storm damage resistance. In fact, some areas require Class 4 impact-resistant shingles on new roofs per local building codes for this exact reason.
However, they’re also worth it for the increased durability. Meeting the high-quality standards to qualify for a class 4 rating doesn’t just make them impact-resistant, but it generally makes them more durable and helps them last longer.
After reading this article, you know how shingles get their class, the difference between the classes, and what class 4 shingles are more impact-resistant than class 3 shingles.
While class 4 shingles are more expensive, they’re well worth it for durability and insurance purposes. Just remember to look at your local codes to determine if class 4 shingles are actually required in your area.
Whether they’re required or you simply want their benefits, you still need to pick a specific shingle. That’s why you need to know the best class 4 shingles available in the roofing industry right now.
Check out The 5 Best Class 4 Impact-Resistant Shingles to learn the top options for homeowners who need or want an impact-resistant shingle.