Hail damage on asphalt shingle roofs
Roofing and building · Cloudbreak team · Updated November 1, 2026 · 16 sources
Definition
Hail damage on an asphalt shingle roof is a bruise, fracture or puncture of the shingle's reinforcing mat, or granules knocked off hard enough to expose the asphalt beneath. Marks that change only how the roof looks, such as minor granule loss, are not counted as functional damage.
How it works
An asphalt shingle is a fiberglass or paper felt mat coated with asphalt and surfaced with mineral granules. A hailstone that hits hard enough flexes the shingle, and the mat fractures first on the underside, where the strain is greatest, then toward the top. The break can be a hole, or only a soft spot that feels like a bruise on an apple when pressed, usually with granules knocked away and asphalt showing.2
Engineers count a mark as damage when it reduces the roof's ability to shed water or shortens its service life. A broken mat counts, because water can reach the nails and joints of the course below. Granules knocked loose without exposing the asphalt have not been found to shorten shingle life, and chipped shingle edges generally are not counted.1
Shingles fail first where they have the least support: hip and ridge caps, valleys, overhanging edges and the strip just above the head lap. Damage is heaviest on the slopes facing the storm. A second layer of shingles laid over the first can leave parts of the top layer unsupported and easier to puncture.1,3,4
Age can lower the hail size that does damage. In the 2011 Dallas/Fort Worth survey, shingles older than 9 years averaged a damage rating of 4.2, against 2.1 for shingles 9 years old or newer or judged to be in good condition; the older shingles that showed embrittlement or deterioration were damaged more often and more severely. The 2016 North Texas survey did not find damage strongly tied to age, which its authors noted differed from their earlier surveys.3,4
How hail damage differs from wear
| Cause | What it looks like |
|---|---|
| Hail | Roughly round spots of lost granules scattered at random, often over a soft spot; freshly exposed asphalt is shiny black and turns light gray as it weathers |
| Foot traffic and handling | A ridge of asphalt and granules around the edge of the mark, which hail does not leave |
| Manufacturing variation | Bare areas lined up in diagonal or straight columns of shingles from one bundle |
| Blisters | Small bubbles whose tops weather away, leaving steep-sided pits that often reach the mat |
| Flaking on old shingles | Bare areas of asphalt already weathered gray |
| Normal shedding | Loose extra granules, called hitchhikers, shed from new shingles; some products keep shedding over the years until asphalt shows |
| Hammer marks | Marks of the same size and shape on every slope, clustered mid-roof, with crushed granules |
Marks also age in known ways. A fresh fracture has sharp edges that round off over the years; in fiberglass shingles the fracture widens but does not visibly spread. Spatter marks, where hail cleaned grime off nearby surfaces, typically last about a year, and dents in vents, gutters and air conditioner fins stay as a record of every storm.1,2
What field surveys and tests found
After the April 11, 2016 North Texas storm, RICOWI teams inspected 99 shingle roofs. The 29 roofs hit by hail up to 0.75 inch had no confirmed damage. Hail of 1 to 1.5 inches gave mixed results, putting the average threshold at about 1.25 inches, and hail of 1.5 inches or larger generally caused significant damage. The worst areas had 100 to 300 damage locations per 100 square feet, and many roofs hit by large amounts of 2.5-inch or larger hail had punctures and occasional fractures in the plywood or OSB below.4
After the May 24, 2011 Dallas/Fort Worth storm, teams inspected 63 shingle roofs. Every roof rated 2 or higher had been hit by hail 1 inch or larger, and 92% of standard shingle roofs with moderate or severe damage had been hit by hail 1.25 inches or larger. Impact-rated shingles averaged a damage rating of 1.3, against 2.5 for standard shingles.3
Haag Engineering's lab tests on shingles weathered about 11 years found aged organic 3-tab shingles damaged half the time by 1-inch ice, fiberglass 3-tab shingles damaged at 1.25 inches and laminated shingles at 1.5 inches. Its field surveys put the threshold at 1 inch for 3-tab and 1.25 inches for laminated shingles, assuming hard hail, square hits, reasonable support and roofs in good or midlife condition.5,2
Quantity can matter as much as size. In 2016, large amounts of hard, wind-driven 1.25 to 1.75-inch hail damaged virtually every shingle on the windward sides of some roofs, while the 2011 survey found size mattered more than count.4,3
An impact rating does not settle how a shingle performs. In IBHS's UL 2218 tests reported in August 2014 on 22 shingle products, none, impact-rated products included, passed more than Class 2 impacts at every location. Using lab-made hailstones, IBHS rated every new shingle it tested at 1.5 inches Good or Excellent. Its 2025 ratings of 24 impact-resistant shingles at 2 inches found most Good and none Excellent.7,16,9,8
Example
| Hail size | Impact energy | What surveys and tests found |
|---|---|---|
| Under 1 in. | Under 1.4 ft-lb | Almost no damage in the 2011 survey, except on badly deteriorated or unsupported material |
| 1 in. | 1.4 ft-lb | Field threshold for 3-tab shingles (Haag) |
| 1.25 in. | 3.4 ft-lb | Field threshold for laminated shingles (Haag); about the average threshold in 2016, with ridge, hip and valley shingles damaged first |
| 1.5 in. | 7.2 ft-lb | Generally significant damage in 2016 |
| 2 in. | 22.9 ft-lb | Size of the UL 2218 Class 4 steel ball; two impact-rated roofs moderately damaged by 1.75 to 2-inch hail in 2011 |
| 2.5 in. and up | 56.4 ft-lb | Punctures through the shingles and occasional fractures in the sheathing (2016) |
Energy climbs far faster than size. Near solid ice, a 2-inch stone carries about 3 times the energy of a 1.5-inch stone (22.9 vs 7.2 ft-lb) and about 16 times that of a 1-inch stone.6
How inspectors check
An inspector looks over each slope, then marks test areas on every slope facing a different direction, away from trees, nearby structures and foot traffic, and counts damaged shingles inside each one. Hail hits are often marked X, foot traffic F and weathering W. Pressing the shingle with fingers finds bruises, and because the damage shows at the weathering surface, the Haag protocol does not need lab tests to confirm it.1
Test areas are commonly 100 square feet, one roofing square, often marked 10 by 10 feet. In Texas, TWIA's 2014 adjusting guidelines call for a test square on each elevation, a 100 square foot area of another shape where a slope is too small, and a count of damaged shingles rather than tabs on 3-tab roofs.15,1
On large roofs and multi-building properties, the Haag protocol adds a test area for each 50 squares of slope and wherever a different shingle type or age appears, and assesses each slope of each roof on its own, regardless of the roofs nearby. That matters on an apartment complex: in 2016, RICOWI found extensive damage on all three buildings it checked at a 35-building complex in Sachse, mostly on west and north slopes, and minimal to no damage on buildings in Wylie half to three quarters of a mile away.1,4
Dents in the aluminum fins of air conditioners give the best gauge of hail size at the building: a dent is typically about 80% as wide as the hailstone.2
The protocol then compares the cost to repair each slope with the cost to replace it. Repair cost is damaged shingles per square, times the cost to repair one shingle, times a difficulty factor of 1 to 2 for age and condition, times the slope's area in squares. Its 1999 example: 10 damaged shingles per square on a 30-square roof in good condition, at $10 a shingle, comes to $3,000.1
Where you'll see it
- Impact ratings on shingle packaging and data sheets: UL 2218 or FM 4473, Class 1 to 4. IBHS recommends UL 2218 Class 4 or FM 4473 Class 3 or 4 for steep-slope roofs in hail-prone areas and, for asphalt shingles, prefers products also rated Good or Excellent on its list.10
- IBHS Hail Impact-Resistant Shingle Ratings, which grade products Excellent, Good, Marginal or Poor against lab-made 2-inch hailstones.9,8
- RICOWI hail investigation reports, which rate each roof 0 to 5, from no apparent damage to severe damage with potential leaks.4
- Commercial property policies with endorsement CP 10 36, which defines roof surfacing to include shingles. It applies only to the buildings listed in its schedule by premises and building number. Paragraph A values roof surfacing at actual cash value instead of replacement cost; Paragraph B excludes cosmetic wind or hail damage, meaning marring, pitting or other superficial damage that alters appearance but does not stop the roof from keeping out the elements as before.11
- The ISO special causes of loss form CP 10 30 (September 2017 edition), which excludes wear and tear, deterioration and latent defects, and does not pay for rain damage inside a building unless a covered cause first damages the roof or walls the rain enters through.12
- Multifamily loan insurance requirements: Fannie Mae and Freddie Mac require property coverage on a replacement cost basis but allow roof coverage on an actual cash value basis.13,14
Questions
- How can you tell if shingles have hail damage?
- Look for roughly round spots where granules were knocked off and black asphalt shows, scattered at random and heaviest on the slopes facing the storm, then press on them: a soft spot means the mat is bruised or fractured. Fresh dents and spatter marks on vents, gutters and air conditioner fins support recent hail, while scuffs, blisters and bare columns from manufacturing look different.1,2
- What size hail damages asphalt shingles?
- Usually about 1 to 1.25 inches and up. Haag's field surveys put the threshold at 1 inch for 3-tab shingles and 1.25 inches for laminated shingles, and RICOWI's 2016 survey found an average threshold of about 1.25 inches. Hail under 1 inch rarely damages shingles unless they are poorly supported and deteriorated.5,4,1
- Is granule loss on shingles hail damage?
- Not by itself. Shingles shed granules as they weather, and granule loss that does not expose the asphalt has not been found to shorten shingle life. On a shingle in good condition, hail strong enough to knock off granules and expose the asphalt usually fractures the mat too.8,1,2
- Can Class 4 shingles get hail damage?
- Yes. A Class 4 roof hit by 3.5 to 4-inch hail in 2016 had scattered large fractures and punctures, and in 2011 one impact-rated roof was severely damaged by 2.5-inch hail. Still, in 2011 impact-rated shingles averaged a damage rating of 1.3, against 2.5 for standard shingles.4,3
- Does hail damage every building in an apartment complex the same way?
- Not always. In 2016, RICOWI found extensive damage at an apartment complex in Sachse, Texas, and minimal to no damage on buildings half to three quarters of a mile away. Engineering protocols assess each slope of each roof on its own.4,1
Cloudbreak
Cloudbreak records every roof section and rooftop unit before a storm, in photos, drone video and notes, so each roof's condition on a given date is on file.
Sources
Written by the Cloudbreak team. Numbers, dates and rules cite the published sources below.
- 1. Haag Engineering: Protocol for Assessment of Hail-Damaged Roofing (Marshall and Herzog, North American Conference on Roofing Technology, 1999)
- 2. Professional Roofing, NRCA: Learn how to identify hail damage on roof systems (Scott J. Morrison, May 2009)
- 3. RICOWI: Hailstorm Investigation Report: Dallas/Fort Worth, TX, May 24, 2011
- 4. RICOWI: Hailstorm Investigation Report: North Texas, April 11, 2016
- 5. Haag Engineering, American Meteorological Society conference paper: Hail Damage Threshold Sizes for Common Roofing Materials (Marshall, Herzog, Morrison and Smith)
- 6. FM: Property Loss Prevention Data Sheet 1-34: Hail Damage (March 2018 edition, interim revision April 2026)
- 7. Insurance Institute for Business & Home Safety: Relative Impact Resistance of Asphalt Shingles: Summary of UL 2218 Impact Tests (August 2014)
- 8. Insurance Institute for Business & Home Safety: Natural Weathering and Hazard Exposure
- 9. Insurance Institute for Business & Home Safety: IBHS Releases Its Most Expansive Impact-Resistant Shingle Ratings to Date (November 19, 2025)
- 10. Insurance Institute for Business & Home Safety: Commercial Roofs Best Practices Guide
- 11. Insurance Services Office, hosted by Independent Insurance Agents of Texas: CP 10 36 10 12: Limitations on Coverage for Roof Surfacing
- 12. Insurance Services Office: Causes of Loss: Special Form, CP 10 30 09 17
- 13. Fannie Mae: Multifamily Selling and Servicing Guide, Part II Chapter 5: Property and Liability Insurance (effective October 26, 2026)
- 14. Freddie Mac: Multifamily Seller/Servicer Guide, Chapter 31: Insurance Requirements
- 15. Texas Windstorm Insurance Association: TWIA & TFPA Property Damage Evaluation Guidelines (version October 7, 2014)
- 16. Insurance Institute for Business & Home Safety: Hail Impact Performance of Asphalt Shingles: At a Glance