Are Metal Roofs Good for Hail?
Quick answer
Yes — metal is one of the best roofing choices for hail. Interlock's aluminum roofing is tested to UL 2218 Class 4, the highest impact-resistance class, meaning it withstands a 2-inch steel ball dropped from 20 feet with no cracking. Aluminum flexes to absorb hail energy rather than shattering like aging asphalt or tile.
How metal roofs handle hail
Hail damages a roof when the impact cracks or punctures it, letting water in — which is exactly what happens to aging asphalt shingles that have lost flexibility, and to brittle clay or concrete tile that shatters. Metal behaves differently. Interlock's heavy-gauge aluminum flexes on impact, spreading and absorbing the energy through its deep, textured profile and four-sided interlock, then returning to shape. It stays watertight through storms that would total a conventional roof.
The UL 2218 Class 4 test
Interlock's roofing is Listed by Intertek to UL 2218 Class 4, the top of the four-class scale. To earn it, the roofing is struck by a 2-inch-diameter steel ball dropped from 20 feet — carrying the energy of a large hailstone — twice in the same spot on two panels, with no cracking on either the top or the underside. It is a deliberately severe test, and passing it is what qualifies the roof for insurance credits.
Impact resistance vs. cosmetic dents
It is worth separating two ideas. UL 2218 grades functional damage — the cracking and rupture that let water in — not cosmetic denting. Any metal surface can theoretically show a mark from an extreme hit, but Interlock's textured profiles are designed to absorb impacts and hide marking, and the Class 4 rating means the roof stays structurally sound and watertight after severe hail. For the life of the roof and for your insurer, that watertight performance is what matters.
Frequently Asked Questions
Are metal roofs good for hail?
Yes — among the best. Interlock aluminum is tested to UL 2218 Class 4, the highest impact class, and flexes to absorb hail rather than cracking. It stays watertight through severe storms that damage asphalt and tile.
Will hail damage a metal roof?
A UL 2218 Class 4 metal roof resists the cracking and rupture that constitute real hail damage. It withstands a 2-inch steel ball from 20 feet with no cracking, so it keeps protecting the home through hail that would ruin a conventional roof.
Does hail dent a metal roof?
UL 2218 measures cracking, not cosmetic denting. Interlock's deep, textured, heavy-gauge aluminum absorbs impact and resists visible marking, and a dent — if any — does not affect the roof's watertight performance.
Do you get an insurance discount for a hail-resistant roof?
Frequently, yes. Many insurers offer a 5%–35% discount for UL 2218 Class 4 roofs, and some states formally recognize the rating. Ask your carrier and provide Interlock's Class 4 certificate.
Sources
- Intertek — UL 2218 Class 4 Listing (SPEC ID 33876) — Impact certification
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Last reviewed 2026-07-11 · Reviewed by Scott Plumptree, Director of Marketing