What Size Hail Can Damage a Roof?

One inch is a weather criterion, not a roof verdict

NOAA describes one-inch or larger hail as one criterion used to classify a thunderstorm as severe. This helps communicate storm danger. It does not tell a homeowner that every exposed roof has functional damage or that an insurer must pay for replacement.

Document the largest hail you can safely observe, along with the time and location. A nearby report can support a storm history, but hail observations are not a substitute for inspecting the building. Avoid rules that promise approval above a particular diameter or promise a roof is safe below it.

What hail observations can—and cannot—tell you

Treat this as a way to organize questions for the inspection. It is not a scoring system, an insurance test square or a formula for calculating replacement entitlement.

What changes the effect of an impact?

The roof assembly matters as well as the hailstone. Material type, age, existing condition, support and impact conditions can affect the result. An inspector should describe actual material responses rather than subtracting an arbitrary amount from a size threshold for every older roof.

For asphalt shingles, ask about fractures, punctures, granule displacement and the condition around suspected marks. Dents on metal require their own evaluation. For low-slope roofs, ask whether the membrane, details or underlying assembly need additional investigation. A single diameter should not be used to declare every roof material damaged or undamaged.

A good report also identifies limits. Not every area can always be accessed safely, and concealed moisture or insulation conditions may require an agreed investigation beyond a basic visual visit. Ask what has been observed and what remains unknown.

What can you safely document after a Minnesota storm?

Wait until conditions are safe. Take photographs from an accessible location, record the date and note visible damage to the building. If practical, photograph hail next to a size reference without going outside during the storm to collect it. Keep any previous roof reports so changes can be discussed.

Do not lift shingles, press marks or walk a suspected damaged roof to create your own test. Altering the material can obscure the condition an inspector needs to assess. Request a professional assessment and tell the contractor about interior leaks, recent repairs or access concerns.

The Minnesota Commerce claim checklist recommends prompt insurer communication and keeping documentation. Ask the insurer about inspection needs before permanent repairs, while addressing necessary temporary protection safely.

What should your inspection and estimate explain?

Ask for photographs grouped by roof area, a description of the material and visible findings, and the basis for any recommended work. The report should distinguish observations from assumptions about causation or concealed damage. If repair is proposed, ask about the surrounding roof and limitations. If replacement is proposed, ask why that scope is needed.

The written construction estimate should identify measured areas, materials, access assumptions, exclusions and how changes will be approved. Keep that estimate separate from questions about deductibles, depreciation or coverage limits, which must be answered under the policy. Neither a roof estimate nor a hail-size chart guarantees a claim outcome.

Read how to compare repair and replacement after hail. When you are ready, the St. Paul hail inspection service explains the assessment and next steps.

Related hail-size questions

Can quarter-sized hail damage a roof?

Quarter-sized hail can be a reason to take storm exposure seriously, but the reported diameter does not establish your roof’s condition. NOAA’s one-inch severe-weather criterion is a warning classification. Ask for a material-specific inspection and photographs rather than treating the weather criterion as a guarantee of damage or insurance coverage.

Does smaller hail mean my roof is definitely undamaged?

A reported size alone cannot certify a roof as undamaged. Reports describe an observation, not a complete inspection of your building. Discuss concerns with a qualified contractor, especially when you notice changes, and keep the recommendation tied to documented findings. Avoid assuming that every dent or loose granule was caused by that storm.

Do insurance companies require one-inch hail to approve a roof claim?

Do not rely on a universal one-inch approval rule. Coverage and settlement depend on your policy and the insurer’s assessment of the loss. Supply relevant weather records and property photographs, but ask the insurer which policy terms and findings support its decision. A contractor cannot turn a weather classification into guaranteed coverage.

Is hail size more important than roof condition?

Both are context, but neither replaces examining the actual roofing. The assessment should consider material condition, roof areas affected, possible causes and whether repair is practical. Ask for the relationship between each observation and the proposed work. A clear report explains uncertainty instead of using a single number to settle every question.

Source guidance

NOAA severe-storm criteria · GAF storm-damage information · NRCA hail guidance.