What Does A Hail Impact Rating Actually Measure?
It measures whether a roofing product tears or cracks when a steel ball hits it. The test is UL 2218, and it sorts products into Classes 1 through 4, with Class 4 the highest. For Class 4 a 2-inch steel ball is dropped from about two stories. A metal panel passes if the ball does not tear, crack, split or open the panel's surface, according to one panel maker's explanation of the standard.
Read that carefully. The pass is about function. Dents are allowed. A Class 4 roof can come out of a storm looking worse and still keep water out, and a roof with no rating can look fine and leak. The rating also belongs to the product as tested, with its substrate and installation. It does not certify your particular roof.
The standard's own scope puts a boundary around the label. UL 2218 does not evaluate weathering, temperature, aging or similar effects, and the standard states that no direct correlation between a roof covering hit by hailstones and the same covering hit by steel balls is currently established. The class compares products under one laboratory drop, in the condition they were tested.
The Insurance Institute for Business & Home Safety runs its own method with laboratory-made hailstones in 1.5-inch and 2.0-inch sizes, built to match the size, density and impact energy of real hail. Its researchers say the lab does not exactly replicate a natural hailstorm, but it allows fair comparisons between products.
How Do Shingles Hold Up To Hail?
Products differ, and the label does not settle it. Asphalt shingles are about 80% of installed residential roofs in the United States according to the Institute, which cites a 2019 Freedonia Group figure, so they are the most studied material. The Institute's early shingle report covers 22 products from five manufacturers.
Its current ratings buy shingles from consumer channels and score each one for dents, tears and granule loss. The point the Institute makes to homeowners is direct: not all products sold as impact-resistant perform the same. A Class 4 label tells you the product passed one test. The Institute rating tells you how it did against its peers.
The failure that matters is the tear. The Institute's leakage study found that small dents allowed negligible leakage and that leakage rose as tears got worse. Pick shingles with a strong tear score.
A second rating decides some upgrade money. The Institute runs the FORTIFIED program, and its hail supplement requires a shingle scored Excellent or Good on the Institute's own shingle ratings. The rule names that score, so a Class 4 label on its own does not meet it.
Ask what the warranty says before you pay for the upgrade. Owens Corning footnotes its own Class 4 product list to say the test results do not guarantee the shingle will resist all weather conditions, and that hail damage is specifically excluded from coverage under its warranty. Other makers write their own terms, so read the one you are offered.
How Do Metal Roofs Hold Up To Hail?
Metal generally takes the hit and dents. In one manufacturer's test modeled on UL 2218, 2-inch steel balls dented a 26 gauge standing seam panel and a 26 gauge corrugated panel, and neither panel punctured or tore. There was less denting over a plywood substrate than with the panel unsupported. The maker described the damage as cosmetic. That is a single maker testing two of its own panels, so treat it as an illustration, not a study.
The Institute has studied the hail performance of low-slope metal roof systems with the Metal Building Manufacturers Association. Its findings are for members only, so this guide does not quote them. What you can take from the existence of the study is that panel profile, gauge, substrate and the roof system all matter, and that a panel result is not a roof result.
The trade research reaches the cosmetic and functional line from the other side. A paper published by ASTM International describes two Metal Building Manufacturers Association projects on simulated hail divots in aluminum zinc coated steel panels, one measuring how fast water drains from a divot and one on coating damage from roll forming. The paper opens with the point that cosmetic damage due to hail is often excluded from coverage, which is why the two words get argued.
Is A Dent The Same As A Leak?
No. A dent changes the surface. A leak needs an opening, which means a tear, a split or a seam that has opened. The standard's pass line sits on that difference. Metal will often fail the look test before it fails the function test, and shingles usually fail by cracking and tearing, which is a function failure. A technical article published by the International Institute of Building Enclosure Consultants on dents in coated steel roof panels draws the same line: a dent is functional damage when it reduces the roof assembly's ability to shed water, as a split, a puncture or a disengaged seam does, and a dent that does none of those is cosmetic.
That difference reaches your policy. Ask your agent whether the policy covers cosmetic damage to metal, and get the answer in writing. We could not find a regulator source on how common cosmetic exclusions are, so this is a question and not a finding.
How Is Hail Size Reported?
A hail report reaches a roof file as a number. The National Weather Service office in Boise publishes a table that turns a measured diameter into an object most people already know, from a quarter inch pea to a four and a half inch grapefruit, and its instruction to spotters is to freeze the stone, measure it and notify the NWS. A homeowner can use the same table from the ground.
The first version of the record is provisional. The Storm Prediction Center posts daily storm reports with a line saying all reports are considered preliminary, and its hail table gives the time, the size, the location, the county and the observer comment behind each one. The reviewed version arrives later in NOAA's Storm Events bulk files, which sit beside a README and a format document that explain the fields.
For scale, the Insurance Information Institute's hail page cites the Storm Prediction Center annual summary at 5,432 hail events of one inch or larger in 2025, against 5,373 in 2024. Those are events reported, not roofs damaged, and a report records the size of the stone rather than the damage it did.
Size is also the part of the inspection a homeowner can do without going up. The National Roofing Contractors Association says a roof system inspection should be done only from ground level, and that every roof a storm passed over should be inspected whatever it looks like from the street.
Which Costs More And What Do I Get Back?
In the sourced local rates linked below, metal prices above shingles on a per-square basis, and standing seam prices above exposed-fastener panels. Rates vary by metro, so use your own metro page. Put a shingle bid and a metal bid side by side with tear-off and extras on separate lines.
The offset is not guaranteed. The Texas Department of Insurance says an insurer might discount for materials less likely to be damaged by hail. Get the number from your insurer before you spend. Then run your claim math in the hail claim calculator and the purchase in the roof replacement cost calculator.
What Should I Ask Before I Choose?
- What is the Institute rating of this exact shingle, and where can I see it?
- Which UL 2218 class is this metal panel listed for, and was it tested over a deck like mine?
- What gauge and profile are you quoting, and what finish warranty covers it?
- What will the insurer discount, in writing?
- Does my policy treat cosmetic dents differently from functional damage?
- Who has installed this product locally, and can I see a roof that has been through a hailstorm?
How Often Does The Record Show A Large Stone Where You Live?
The stored storm record counts hail days by metro area. A day enters the count when a report of one inch or larger comes from a county in the metro, and the record also marks the days whose largest stone reached 1.75 inches. The table below sums both counts over the five complete years, 2021 through 2025, so a partial year cannot pull a metro's figure down.
Put the stone column beside the impact test, and keep the two apart. The Class 4 line in UL 2218 drops a 2 inch steel ball on a product in a laboratory. The stored record marks a day at 1.75 inches. One number comes from a test of a roof covering, the other counts days on which a person reported a stone at or above that size somewhere in the metro's counties.
| Metro area | Hail days, 2021 to 2025 | Days with a stone of 1.75 inches or larger | Share of hail days at that size | Largest stone in the file (inches) |
|---|---|---|---|---|
| Dallas-Fort Worth | 98 | 50 | 51% | 5 |
| Oklahoma City | 76 | 34 | 45% | 4 |
| Denver | 63 | 20 | 32% | 3.5 |
| Kansas City | 63 | 20 | 32% | 5 |
| St. Louis | 57 | 26 | 46% | 3.75 |
| Minneapolis | 51 | 22 | 43% | 3.5 |
| Austin | 45 | 21 | 47% | 4 |
| San Antonio | 45 | 21 | 47% | 5.5 |
| Chicago | 43 | 11 | 26% | 4.8 |
| Nashville | 43 | 15 | 35% | 3 |
| Atlanta | 40 | 10 | 25% | 2.75 |
| Houston | 37 | 10 | 27% | 2.75 |
| Charlotte | 31 | 7 | 23% | 4 |
| Orlando | 22 | 4 | 18% | 2.75 |
| Phoenix | 14 | 6 | 43% | 2 |
| Tampa | 8 | 1 | 13% | 3 |
Source: NOAA Storm Prediction Center daily storm reports, read from the stored hail file in this repository and built on October 19, 2026. The five-year totals cover reports fromJan 1, 2021 through the end of 2025. The largest-stone column also counts 2026, which is a partial year in the file, through Oct 17, 2026. Every report is preliminary: the service posts each one before its review, and a later review can change a size or a place.
A report is a point observation, not a roof inspection. It says a stone of a stated size was measured at a place and time, and it says nothing about the roof on a particular house. What the counts can do is set the question. A metro with many days at that size is one where the exact product rating and the installer's own evidence on your roof type deserve more weight. A metro with few is one where price, warranty wording and wind are likelier to decide the purchase, and the hail history pages linked below show the per-year rows behind each count.
When Does This Comparison Not Apply?
It leaves out a lot, and your situation may sit in the gap.
- Large enough hail damages any material, so a rating narrows risk and does not remove it
- Wind, fire and an HOA's rules may matter more than hail where you live
- Tile, slate and synthetic products are not covered here
- On a low-slope roof the answer is a membrane system, not shingles or panels
- If you plan to sell soon, the premium may not come back to you
Hail history is the tie-breaker. If your area rarely sees damaging hail, an upgrade buys less. If it sees hail often, it buys more. The hail history pages below show the recorded reports for the metros we cover.
What Else Do Homeowners Ask About Metal Roofs And Hail?
- How much does a metal roof cost?
- More than asphalt shingles per square in the sourced local rates on this site, and the gap depends on the type of metal. Standing seam and exposed-fastener panels price differently, and so do pitch and tear-off. The reading list below links dated local ranges for both metal types and for shingles, so you can compare the same house on each.
- How much does a roof replacement cost?
- Measured squares times the per-square price of the material, plus tear-off, underlayment, flashing, decking repair and the permit. Material is the biggest swing. Ask for two bids on the same house, one in shingles and one in metal, with each extra on its own line.
- Who are the best hail damage roof repair companies?
- A local roofer you can verify, with a written warranty and a bid that names its materials. Our rankings research roofers metro by metro with every fact linked to its source. Metal and impact-rated shingles both need installers who have done the work, so ask for recent examples on your roof type.
- Which roofing companies are BBB accredited?
- Accreditation is something a company applies for and the BBB reviews, and it is not a license. Each company page on this site links to the BBB profile we checked. An unaccredited company can still hold a clean record, so read the complaint history and years in business next to the accreditation flag.
- What does a Class 4 impact rating mean?
- Class 4 is the top class of the UL 2218 impact test. A 2-inch steel ball is dropped onto the roofing from about two stories, and for metal panels to pass the ball must not tear, crack, split or open the surface. The test allows cosmetic dents. It rates the tested product, not every roof built with it.
- Will hail dent a metal roof?
- It can. In one panel maker's own test modeled on UL 2218, 2-inch steel balls dented 26 gauge standing seam and corrugated panels but did not puncture or tear them. Dents change appearance, and whether they change the roof's function depends on whether the metal tears or the seams open.
- Do impact-resistant shingles hold up better in hail?
- Some do, but the Insurance Institute for Business & Home Safety found that not all impact-resistant shingles perform the same. It buys shingles at retail and rates them for dents, tears and granule loss. Ask for the Institute rating of the exact product, not only the Class 4 label.
- Will my insurance cost less with a hail-resistant roof?
- It might. The Texas Department of Insurance says an insurer might give a discount for roofing materials less likely to be damaged by wind, hail or fire. Ask your insurer for the discount in writing before you pay for the upgrade, and ask whether your policy treats cosmetic dents on metal differently.
- Is a dented metal roof covered by insurance?
- Policies differ, so read yours for any cosmetic damage language and ask your insurer plainly. Some policies separate damage that affects how the roof works from damage that changes only how it looks. We found no regulator source stating how common such terms are, so treat it as a question for your agent.
- Can hail damage a roof anywhere?
- Yes. The Institute states that hail can occur in any strong thunderstorm, so it is a threat everywhere, though some regions see more of it. Local hail history helps you judge how much impact resistance is worth paying for, and our hail history pages in the reading list below show recorded reports for the metros we cover.
Which Guides Should I Read Next?
- Hail Damage Roof Repair By Metro In Texas: Hail days and insurer wind and hail losses for every Texas metro on the site, then the inspection, claim steps, contractor checks and warning signs after a storm.
- How Long After Hail Do Roof Permits Rise?: The days between each hail day and the first week of unusually high re-roof permits, computed from public storm and city permit files.
- Roof Replacement Cost By Metro In Texas: Installed cost per roofing square, city permit valuations and insurer Wind losses for every Texas metro on the site, each figure with its source and date.
Where Can I Read More Or Run The Numbers?
- Hail claim calculator: run the deductible and depreciation arithmetic on your policy.
- Roof replacement cost calculator: price shingles, metal and tile for your roof.
- Methodology: how this site researches and sources its numbers.
- How Do I Read A Roofing Estimate?: The lines a roofing estimate should price separately, how to compare bids, and the contract language to refuse.
- Should I Repair Or Replace My Roof?: What decides between a repair and a full replacement, and what an insurer will and will not pay for.
- How Do I Spot A Storm Chaser Roofer?: The door-knock, contract and deductible tells that separate a storm chaser from a local roofer.
- How Do I Pick A Roofer After A Storm?: The inspection, the insurance claim steps, the contractor checks and the warning signs, with a public source behind every lookup.
- How Long After Hail Do Roof Permits Rise?: The days between each hail day and the first week of unusually high re-roof permits, computed from public storm and city permit files.
- Roof Replacement Cost By Metro In Texas: Installed cost per roofing square, city permit valuations and insurer Wind losses for every Texas metro on the site, each figure with its source and date.
- Roof Permit Fees By Metro In Texas: Whether a re-roof needs a permit, the residential fee, who pulls it and the fee schedule behind it for each Texas city on the site, with Not published where a schedule states no flat fee.
- Hail Damage Roof Repair By Metro In Texas: Hail days and insurer wind and hail losses for every Texas metro on the site, then the inspection, claim steps, contractor checks and warning signs after a storm.
- What We Learned Reading BBB Files: what a BBB grade, an accreditation and a complaint count do and do not tell you about a roofer.
- Metal roof cost in San Antonio: what the public permit files hold on metal roofs, and what they cannot say.
- Metal roof cost in Dallas-Fort Worth: what the public permit files hold on metal roofs, and what they cannot say.
- Metal roof cost in Houston: what the public permit files hold on metal roofs, and what they cannot say.
- Metal roof cost in Austin: what the public permit files hold on metal roofs, and what they cannot say.
- Roof replacement cost in San Antonio: sourced local per-square rates for shingles, metal and tile.
- Roof replacement cost in Dallas-Fort Worth: sourced local per-square rates for shingles, metal and tile.
- Roof replacement cost in Houston: sourced local per-square rates for shingles, metal and tile.
- Roof replacement cost in Austin: sourced local per-square rates for shingles, metal and tile.
- Hail history in San Antonio: recorded hail reports by year from the NOAA Storm Events database.
- Hail history in Dallas-Fort Worth: recorded hail reports by year from the NOAA Storm Events database.
- Hail history in Houston: recorded hail reports by year from the NOAA Storm Events database.
- Hail history in Austin: recorded hail reports by year from the NOAA Storm Events database.
- Sourced local rates for San Antonio, gathered 2026-08-25: architectural asphalt shingle $450 to $700 per square; standing seam metal $1,000 to $1,600 per square; exposed-fastener metal panel $500 to $900 per square. Rates differ by metro, so open the cost page for yours.
Where Do These Facts Come From?
- Western States Metal Roofing, Impact resistance test on metal roof panels (a manufacturer’s own explanation of UL 2218 and its test of two panels). https://www.westernstatesmetalroofing.com/blog/metal-panel-impact-resistance-test. Fetched 10 October 2026.
- UL Standards & Engagement, UL 2218, Impact resistance of prepared roof covering materials (product page with the standard scope). https://shopulstandards.com/ProductDetail.aspx?productId=UL2218. Fetched 25 October 2026. The scope states that the test does not evaluate weathering, temperature, aging or similar effects, and that no direct correlation between the performance of a roof covering hit by hailstones and by steel balls is currently established.
- Insurance Institute for Business & Home Safety, Hail research overview. https://ibhs.org/hail/. Fetched 10 October 2026.
- Insurance Institute for Business & Home Safety, Relative hail impact resistance of asphalt shingles. https://ibhs.org/hail/relative-impact-resistance-of-asphalt-shingles/. Fetched 10 October 2026.
- Insurance Institute for Business & Home Safety, Hail impact-resistant shingle ratings. https://ibhs.org/hail-impact-resistant-shingle-ratings/. Fetched 10 October 2026.
- Insurance Institute for Business & Home Safety, Water leakage vulnerabilities for shingles with hail damage. https://ibhs.org/hail/water-leakage-vulnerabilities-for-shingles-with-hail-damage/. Fetched 10 October 2026.
- Insurance Institute for Business & Home Safety, Hail impact performance of low-slope metal roofing. https://ibhs.org/hail/hail-impact-performance-of-low-slope-metal-roofing/. Fetched 10 October 2026.
- Insurance Institute for Business & Home Safety, FORTIFIED program, Hail protection that works. https://fortifiedhome.org/article/hail-protection-that-works/. Fetched 25 October 2026. The article states that a shingle roof seeking the Hail Supplement to a FORTIFIED designation must use a product with an overall score of Excellent or Good on the Institute shingle ratings.
- Owens Corning, Impact resistance shingles, class rating. https://www.owenscorning.com/en-us/roofing/shingle-class-rating. Fetched 25 October 2026. The page lists the products it classifies as UL 2218 Class 4 and footnotes the list to say the test results do not guarantee the shingle will resist all weather conditions, and that hail damage is specifically excluded from coverage under the shingle warranty.
- ASTM International, New research on hail damage to Al-Zn alloy coated steel roofing (STP1650). https://store.astm.org/stp165020220099.html. Fetched 25 October 2026. The abstract describes two Metal Building Manufacturers Association projects on simulated hail divots in coated steel panels, and opens with the point that cosmetic damage due to hail is often excluded from coverage.
- International Institute of Building Enclosure Consultants, Fall Exclusive: A Deep Dive into Hail-Caused Dents (a study of corrosion resistance within dents in Galvalume-coated steel roof panels). https://iibec.org/publication-post/fall-exclusive-a-deep-dive-into-hail-caused-dents-a-study-of-corrosion-resistance-within-dents-in-galvalume-coated-steel-roof-panels/. Fetched 1 November 2026. Defines functional damage as damage, typically dents or deformations, that reduces the roof assembly’s ability to shed water, and says hail-caused dents that have not split, fractured or punctured the metal, or otherwise compromised its ability to resist moisture intrusion such as by disengaging a seam, are cosmetic.
- Texas Department of Insurance, Insurance and your roof. https://www.tdi.texas.gov/tips/replacing-your-roof.html. Fetched 10 October 2026. Page last updated 4/1/2026.
- National Weather Service, Estimating hail size (Boise, Idaho, forecast office). https://www.weather.gov/boi/hailsize. Fetched 25 October 2026. The table turns a hail diameter in inches into a familiar object, from a quarter inch pea to a four and a half inch grapefruit, and the page tells spotters to freeze it, measure it and notify the NWS.
- NOAA Storm Prediction Center, Storm reports. https://www.spc.noaa.gov/climo/reports/. Fetched 10 October 2026. Daily reports of hail, wind and tornadoes. Same-day reports are preliminary until NCEI publishes its reviewed record.
- NOAA National Centers for Environmental Information, Storm Events database (bulk files). https://www.ncei.noaa.gov/pub/data/swdi/stormevents/csvfiles/. Fetched 10 October 2026. The reviewed record, published with a lag of weeks to months.
- Insurance Information Institute, Facts and statistics: hail. https://www.iii.org/fact-statistic/facts-statistics-hail. Fetched 25 October 2026. The page cites the Storm Prediction Center annual severe weather summary at 5,432 hail events of one inch or larger in 2025, against 5,373 in 2024.
- National Roofing Contractors Association, Storm damage repair caution for homeowners and business owners (July 27, 2022). https://www.nrca.net/RoofingNews/nrca-urges-homeowners-and-business-owners-affected-by-severe-weather-to-use-caution-when-repairing-their-roof-systems.7-27-2022.10442/details/story. Fetched 25 October 2026. The release says a roof system inspection should be done only from ground level, that every roof a storm passed over should be inspected whatever it looks like, and that a consumer should keep a healthy skepticism about the lowest bid.
- Better Business Bureau, Get accredited. https://www.bbb.org/get-accredited. Fetched 26 October 2026. The page invites a business to apply for BBB Accreditation, says the local BBB then contacts the business to learn more about it, and states that accredited businesses pay an annual dues investment. It describes accredited businesses as ethical and vetted. It does not describe accreditation as a license.
- Best Roofers Ranked methodology. How the site researches and ranks roofers. Rates and counts on metro pages carry their own dated sources.