Glossary

Class 4 roof

A roof covering that earned the top impact rating under the UL 2218 test, which simulates hail with a dropped steel ball, and that insurers may discount.

Also called: UL 2218 Class 4, Class 4 impact-rated roof, Class 4 shingles

A Class 4 roof uses a covering that earned the top rating under UL 2218, a standard test of impact resistance. Class 4 products survive a 2-inch steel ball dropped from 20 feet, twice on the same spot, without cracking through. Lower ratings, Class 1 to Class 3, use smaller balls dropped from lower heights.

The test allows cosmetic damage such as dents. It checks for cracks, not appearance. It also uses new, unweathered samples and does not model aging, so it is a useful benchmark, not a promise that a roof survives any hailstorm. For metal roofing, UL generally recognizes a panel as Class 4 only if the proper label is attached. A different standard, FM 4473, uses ice balls.

Insurers in hail states may give a premium credit for a Class 4 roof, but credits vary by state and company and are not guaranteed. To claim one, send your agent the product's rating documentation and the installation invoice. A credit sometimes arrives alongside a cosmetic damage exclusion that changes what the policy pays after hail, so ask about both before you decide. The guide impact-resistant (Class 4) roofs and hail discounts covers the savings, and the roof and mitigation upgrade payback calculator estimates payback.

Last reviewed October 10, 2026

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Related terms

Impact-resistant roof A roof built with a covering tested to withstand hail and debris impact, which can earn a premium credit from some insurers in hail-prone states. Hail damage Dents, bruises, cracks and punctures that falling ice causes to roofs, siding, windows and outdoor equipment, covered under the windstorm or hail peril. Cosmetic damage exclusion An endorsement that excludes hail dents, pitting and surface marks that do not stop a roof or siding from doing its job, often in exchange for a lower premium. Mitigation credit A premium discount for building features shown to reduce storm or wildfire damage, such as a reinforced roof, impact windows or defensible space. Wind/hail deductible A separate amount you pay first, flat or a percentage of the dwelling limit, on damage from wind or hail in place of the standard flat amount.

Related guides

Hail damage claims: roofs, siding and windows How hail claims are inspected and paid, why the roof settlement, the wind/hail deductible and cosmetic exclusions decide the check, and what to do first. Impact-resistant (Class 4) roofs and hail discounts What a Class 4 rating tests, which roofs qualify, how insurers and states handle the discount, and the cosmetic-damage catch to check before you upgrade. Metal roofs and insurance How insurers treat metal roofs: hail dents and cosmetic damage exclusions, fire, wind and hail credits, age limits, matching, and what to ask before you buy. How roof age and material affect premiums Roof age sets a rating factor and decides how storm damage is settled; material and impact ratings shape credits. What a new roof saves and how to document it.

Related states

Arkansas Arkansas home insurance: State Farm and Farm Bureau lead, hail and tornadoes push premiums above average, no FAIR plan, and a new FORTIFIED roof grant program. Nebraska Nebraska has no FAIR plan. State Farm leads, hail drives a $2,142 average HO-3 premium, and a valued policy law pays full limits on total losses. South Dakota South Dakota home insurance: State Farm and American Family lead a $555 million market where hail and wind drive claims and no FAIR plan exists.