What does Class 4 mean on a shingle?
Class 4 is the top rating in UL 2218, the impact test most shingle makers publish. A steel ball is dropped twice on the same spot from the height that gives it the energy of a falling hailstone of the same size, and the shingle passes when no crack shows on its back. The class is the size of the ball it survives, from 1.25 inches for Class 1 to 2 inches for Class 4 (the table below).
GAF describes its Class 4 test as a 2-inch steel ball dropped twice from 20 feet onto each target spot. Some lines also carry FM 4473 Class 4, a second impact standard; Owens Corning lists both for Duration FLEX.
Two things the rating does not say. It is a laboratory result, not a promise that a roof comes through every storm unmarked. And in 2019 the Insurance Institute for Business & Home Safety (IBHS) began testing shingles with lab-made hailstones built like real ones, scoring the dents, granule loss and tears each shingle shows instead of a pass or a fail, because a steel ball and a hailstone do not hit the same way.
| Class | Steel ball diameter |
|---|---|
| Class 1 | 1.25 inches |
| Class 2 | 1.50 inches |
| Class 3 | 1.75 inches |
| Class 4 | 2.00 inches |
How do shingles and metal compare in hail?
The difference that matters in hail is what the material does when it is hit. A standard asphalt shingle is stiff and can crack or bruise. A rubberized shingle (SBS or polymer-modified asphalt) flexes, which is what lets it pass the 2-inch test. Metal does not crack, but it dents, and a dent is permanent.
In the IBHS summary of UL 2218 results, impact-resistant shingles passed far more of their impact locations than basic shingles of the same style. The cost of each option is a separate question, covered in what sets the price of a roof replacement.
| Roof covering | Impact rating | What hail does to it | Worth knowing |
|---|---|---|---|
| Standard architectural shingle | Usually none, or a lower class | Bruises, cracks and knocked-off granules from large hail | The common shingle, and the least hail protection of the three |
| Class 4 rubberized shingle | UL 2218 Class 4 | Flexes under the hit instead of cracking; very large hail can still damage it | Same dimensional look; may qualify for an insurance discount |
| Metal panels | Impact-rated panels exist; check the panel | Dents. A dent alone seldom harms how a panel works; seams, caps and trim are where hail does real damage | A policy may treat dents as cosmetic damage and not pay for them |
Which Class 4 shingles does Rocket Roofing General Contractor install?
Malarkey is our flagship shingle. Its Vista, Legacy and Windsor lines are built on NEX polymer-modified (rubberized) asphalt and carry a UL Class 4 impact rating, and Malarkey says they meet IBHS FORTIFIED Roof requirements.
We are also an Owens Corning Preferred Contractor and a GAF Certified Residential Roofing Contractor, so their impact-rated lines are open to you as well:
- Owens Corning Duration FLEX: SBS polymer-modified asphalt, rated UL 2218 Class 4 and FM 4473 Class 4.
- GAF Timberline AS II: SBS-modified asphalt, rated UL 2218 Class 4.
The right line depends on the roof, the look you want and what your insurer recognizes, which is what the free inspection is for.
Does a Class 4 roof lower insurance in Nebraska?
It can. The Nebraska Department of Insurance encourages asking your insurer about potential savings for impact-resistant roofing rated Class 3 or Class 4. Whether there is a discount, and how much, is up to the insurer, so ask before you choose, and ask what proof of the shingle's rating they want after it is installed.
If an insurance claim is paying for a new roof, an upgrade to Class 4 is usually yours to pay as its own line. How a claim works from the first call to the final check is in our guide to Nebraska roof insurance claims.
When does a dent or a mark count as hail damage?
Insurers sort hail damage into two kinds. Functional damage makes the roof worse at shedding water or shortens its life, such as a cracked shingle or a fracture through the mat. Cosmetic damage changes only how the roof looks.
That line matters most for metal. IBHS reports no evidence so far that dents change how a metal roof works, and InterNACHI notes that hail seldom does functional damage to metal panels: when it does, it is usually at a seam, a ridge or hip cap, the trim, or where panel edges meet. Whether a policy pays for cosmetic damage depends on the insurer and how the policy is written, so read yours before choosing metal for hail. How to spot hail damage on any roof is in how to tell if your roof has hail damage.