Class 3 vs. Class 4 Shingles: What the Rating Actually Tells You

Here's the most important thing to know: Class 4 does not mean hail-proof.

There is no asphalt shingle we'd confidently describe that way.

Class 3 and Class 4 are impact-resistance classifications. They tell you something useful about a roofing product's ability to withstand a standardized laboratory impact.

They do not tell you the maximum hailstorm your roof will survive.

That's an important distinction in North Texas.

What do the numbers mean?

Under the UL 2218 impact test:

Class 4 is the highest classification in that particular standard.

But here's where it gets interesting.

Passing Class 4 establishes a threshold.

It doesn't establish a ceiling.

Imagine two students taking a pass/fail test requiring a score of 80. One gets an 81. The other gets a 99. Their report cards both say PASS.

Impact classifications have a similar limitation.

Two shingles can carry the same classification while having meaningfully different performance characteristics.

That's one reason organizations such as the Insurance Institute for Business & Home Safety have developed more realistic hail-testing protocols capable of differentiating performance among impact-resistant shingles.

So is Class 4 worth buying?

Sometimes absolutely.

Sometimes the price difference doesn't make sense.

Our usual recommendation for North Texas is simpler:

Start at Class 3 or better. Then compare the actual products and the actual cost difference.

The financial margin between a Class 3 and a Class 4 roof can occasionally be small enough that upgrading is easy to justify.

Other times the premium is large enough that we'd rather see the homeowner make the decision based on budget, insurance considerations and the characteristics of the particular product—not simply because 4 is greater than 3.

What does real-world experience look like?

Does Class 4 mean it survives 2-inch hail?

No.

UL 2218 uses standardized impacts to classify material performance. Real hail is messier.

Actual damage depends on variables including:

• hailstone density and hardness
• wind
• impact angle
• roof slope
• shingle age
• temperature
• installation
• substrate
• repeated impacts

Laboratory classifications are useful comparison tools.

They aren't force fields.

Not every impact-resistant shingle performs equally

This is probably the most overlooked part of shopping for an impact-resistant roof.

Modern hail research has found meaningful performance differences among products that consumers might otherwise place in the same general “impact-resistant” bucket.

So don't stop your research at: “Is it Class 4?”

Ask: “How does this particular shingle perform?”

That's a better question.

Which brands does Blue Roofing recommend?

We hesitate to publish a permanent ranking.

The major roofing manufacturers spend enormous resources developing and improving their products, and manufacturing quality changes over time.

During a long career in roofing, we've seen excellent manufacturers occasionally encounter product or manufacturing issues.

Today's ranking could therefore become tomorrow's outdated article.

Our current recommendations frequently include products from:

• Malarkey
• Owens Corning
• GAF

Higher-end GAF products such as UHDZ and ArmorShield II can also be worth evaluating depending on the project.

But we'd rather recommend a specific product for a specific house than crown one manufacturer the permanent winner.

Bottom line

For North Texas:

• Standard architectural shingle: economical baseline.
• Class 3: where we'd generally prefer homeowners to begin.
• Class 4: potentially worthwhile when the product performance and upgrade cost justify it.

And remember: impact-resistant is not the same thing as impact-proof.

Buy the actual product—not just the number printed next to it.