Class 4 Impact-Resistant Shingles | UL 2218

Quick Answer

UL 2218 is the impact-resistance test most commonly used to rate asphalt shingles for hail performance. Class 4 is the highest rating — the shingle does not crack when struck by a 2-inch steel ball dropped from 20 feet, simulating roughly the impact energy of a large hailstone. Class 4 shingles typically last longer in hail-prone markets, are required by code in several Colorado jurisdictions (Lakewood, Fort Collins, Colorado Springs, parts of Boulder County), and may qualify for an insurance premium discount through some carriers.

What UL 2218 Actually Measures

UL 2218 is an impact-resistance test, not a guarantee that a roof will not be damaged in any storm. The test drops a steel ball of a specified diameter onto the shingle from a specified height and inspects the underlying mat for cracks. Class 1 (smallest ball) through Class 4 (largest) corresponds to increasing impact energy. Class 4 is the highest commercial rating available and is what most Colorado contractors mean by 'impact-resistant'.

Insurance discounts vary by carrier and policy and are not guaranteed; AC INC Roofing supplies the manufacturer impact-rating documentation, the homeowner submits it to their carrier. Confirm any potential discount in writing with your insurance agent before assuming it applies.

Where Class 4 Is Required by Code in Colorado

Several Colorado jurisdictions have adopted code requirements that effectively mandate Class 4 (or other equivalent impact-resistance ratings) on most residential roof replacements within their boundaries. AC INC Roofing pulls the requirement from the local license database for every project and quotes Class 4 by default in those jurisdictions.

• Lakewood — Class 4 required on residential replacements
• Fort Collins — Class 4 required on residential replacements
• Colorado Springs (Pikes Peak Regional Building Department) — Class 4 required
• Boulder County — Class 4 required in unincorporated areas
• Other jurisdictions are reviewing similar requirements year by year

How Class 4 Interacts With Insurance

Many Colorado homeowners insurance carriers offer a premium discount for installing UL 2218 Class 4 impact-resistant shingles — typically 5–30% off the wind/hail portion of the premium. The exact discount, eligibility rules, required documentation, and any waiting period vary by carrier. AC INC Roofing provides the manufacturer’s impact-rating documentation with every Class 4 install so the homeowner can submit it to their carrier; we cannot guarantee a specific discount because the discount is determined by the carrier and the policy.

Trade-offs to Know Before Choosing Class 4

Class 4 systems are typically 10–20% more expensive than equivalent non-impact systems and have a slightly narrower color/style selection (most major manufacturers carry their flagship Class 4 line in 6–10 colors vs 12–20 for the standard product). Some HOAs require approval before swapping to a Class 4 product if the new color profile differs from the prior shingle. We help homeowners pull HOA approval and weigh the higher up-front cost against the long-term hail performance and any insurance discount.

Frequently Asked Questions

Will Class 4 shingles eliminate hail damage?

No. Class 4 shingles dramatically improve impact resistance versus standard asphalt and typically reduce hail damage in moderate hail events, but very large hail (2.5"+) can still damage Class 4 product. The rating is about hail performance, not invincibility — we still recommend a post-storm inspection on Class 4 roofs after major hail events.

How much insurance discount can I expect for a Class 4 roof?

It varies. We see Colorado carrier discounts ranging from roughly 5% to 30% off the wind/hail portion of the premium, with State Farm, USAA, Allstate, and Farmers all offering some version of the program in our market. The actual dollar discount depends on your carrier, your policy, and your dwelling coverage. Confirm directly with your insurance agent before assuming a specific discount.

Are Class 4 shingles worth the extra cost?

For homes in hail-prone Colorado neighborhoods, often yes — especially when an insurance discount partially offsets the higher up-front cost. For homes outside the hail belt or that already have a low wind/hail premium, the math may not pencil. We give homeowners a side-by-side cost comparison (standard product, Class 4 product, and 10-year cumulative premium impact) so they can make the call with real numbers.

What manufacturers does AC INC Roofing install for Class 4?

We routinely install Atlas StormMaster Shake and Pinnacle Pristine Impact, CertainTeed Landmark IR / Landmark ClimateFlex, GAF Timberline AS II, Owens Corning Duration FLEX / Duration STORM, and Malarkey Vista AR / Legacy Scotchgard / Highlander NEX (SBS-modified, naturally impact-resistant). All of these are UL 2218 Class 4 rated and qualify for the manufacturer’s Class 4 impact warranty.

Will my HOA approve a Class 4 product?

Most Colorado HOAs that allow asphalt shingles allow Class 4 products in similar colors. We provide architectural-review-board (ARB) sample boards and the manufacturer’s color sheet so the HOA can sign off before we order materials. If the HOA requires a specific shingle that is not available in Class 4, we flag that early so the homeowner can decide whether to seek an HOA variance.