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Impact Resistance

A shingle’s tested ability to withstand hail impact without cracking or fracturing — and the rating that determines whether your roof qualifies for an insurance discount and how it performs in Colorado’s hail corridor.

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What Impact Resistance Is

Impact resistance is the ability of a roofing material to withstand hail impact without cracking, fracturing, or losing structural integrity.

For asphalt shingles, this performance is tested under the UL 2218 standard, which simulates hail impact using a steel ball dropped from a controlled height.

Shingles are classified into four impact resistance levels — Class 1 through Class 4 — with Class 4 representing the highest level of resistance.

The UL 2218 Testing Standard

Test Method

A steel ball is dropped from 20 feet onto the shingle to simulate hail impact at terminal velocity. The shingle is then inspected for cracking or structural failure.

Class Ratings

  • Class 1 — 1.25″ impact
  • Class 2 — 1.5″ impact
  • Class 3 — 1.75″ impact
  • Class 4 — 2″ impact (highest rating)

Each class must pass impact tests at multiple points on the same sample.

What the Rating Does Not Measure

Impact resistance ratings measure resistance to cracking and fracture — not all forms of damage.

They do not account for:

  • Granule Loss
  • Surface wear from smaller hail
  • Cosmetic damage

A Class 4 shingle may still show visible impact marks or granule displacement without structural failure.

Why It Matters in Colorado

Frequent Hail Events

Colorado’s Front Range regularly experiences hailstorms with stones in the 1″–2″ range — where impact resistance ratings directly affect performance.

Insurance Premium Discounts

Many carriers offer 20–30% premium discounts for verified Class 4 installations.

Reduced Claim Frequency

Higher impact resistance reduces the likelihood of structural damage in moderate storms.

Carrier Requirements

Some insurers require Class 4 shingles for continued coverage or for Replacement Cost Value (RCV) eligibility.

Impact Resistance and Insurance Claims

  • Depreciation treatment — may differ for Class 4 shingles
  • Like-kind replacement — Class 4 roofs should be replaced with Class 4
  • Estimate accuracy — verify correct material specification
  • Discount activation — requires documentation after installation

If your estimate specifies standard shingles when your roof had Class 4, it is under-scoped.

Class 4 Practical Considerations

Cost Difference

Typically 10–20% more than standard architectural shingles.

Product Identification

Often labeled “IR” or “Impact Resistant” — verify with manufacturer data sheets.

Documentation Requirements

Carriers require proof of installation to apply premium discounts.

Warranty

Often equal or better than standard shingles in the same product line.

Common Questions

Are Class 4 shingles hail-proof?

No — they reduce damage, but do not eliminate it.

How do I claim the insurance discount?

Submit your contractor invoice and product documentation to your carrier.

Do I need to install Class 4 shingles?

Not always — but they are often the best long-term option in Colorado.

Can I upgrade during a claim?

Yes — you pay the cost difference between standard and Class 4 materials.

How Claim Advocacy Helps

  • Product verification — identifying existing shingle class
  • Estimate review — ensuring like-kind replacement
  • Upgrade analysis — evaluating cost vs. savings
  • Discount documentation — ensuring carrier compliance
  • Carrier requirement review — confirming coverage conditions

Impact resistance is one of the most important factors in how a roof performs in Colorado’s hail environment. Understanding your current roof’s rating — and ensuring your replacement matches or improves it — directly affects both your insurance costs and your roof’s long-term durability.

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📧 gerald@winik.io

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