The right shingles for storms aren’t picked by looks or by a sales pitch. They’re picked by lab ratings, and every one of those ratings started as a crash test.
- Specimen
- Asphalt roof shingle
- Hazards
- Hail impact · wind uplift
- Protocols
- UL 2218 · FM 4473 · ASTM D3161 · ASTM D7158 · FORTIFIED
Car makers crash vehicles so you can compare safety ratings. Roofing works the same way: labs drop steel balls on shingles and pull at them with wind until they lift. The result is a short code, like Class 4 or Class H, that tells you how the shingle held up.
This report walks through each test and lets you run a drop test yourself, so you can read the results before you pick shingles for storms.
Read time · 8 min
The top shingles for storms pass two tests. UL 2218 Class 4 is the top impact rating, and ASTM D3161 Class F or ASTM D7158 Class H is the top wind rating. A FORTIFIED Roof then checks the whole system.
Why Shingles for Storms Get Crash-Tested
Ohio roofs take hail from above and wind at the edges. You can’t wait for a real storm to see how a roof holds, so the industry built repeatable tests that grade shingles for storms the same way every time.
The National Weather Service calls a thunderstorm severe when it drops hail 1 inch in diameter (quarter size) or larger. If you’ve already been through one, our guide to the signs of hail damage shows what to look for.
Ratings let you compare shingles for storms side by side. They don’t predict every storm; they show which product held up under the same measured abuse.
Two Hazards, Two Families of Tests
Impact: UL 2218 and FM 4473 grade how a shingle handles a strike.
Wind: ASTM D3161 and ASTM D7158 grade how well it stays sealed. Shingles for storms need a pass in both.
The Steel-Ball Test Behind Every Class 4 Label
UL 2218 is the hail test most shoppers hear about. According to the Insurance Institute for Business & Home Safety (IBHS), the test uses steel balls instead of ice, sized by class: 1.25 inches for Class 1, 1.50 inches for Class 2, 1.75 inches for Class 3 and 2.00 inches for Class 4. Each ball is dropped from the height needed to match the energy of a hailstone of the same size.
- Mount the specimenShingles are installed on a test deck the way they’d sit on a roof.
- Pick the ballThe steel ball size sets the class being tested, from 1.25 to 2 inches.
- Strike twiceEach target spot takes two hits from the same ball, per the IBHS write-up.
- Inspect the backTechnicians turn the shingle over and look for any opening.
IBHS notes that loose granules or top-surface marks alone don’t count as failures. The question is simple: did the strike open a path for water? Shingles for storms that survive the 2-inch ball earn Class 4.
What about FM 4473? Where UL 2218 drops steel, IBHS describes FM 4473 as a method that tests with pure ice spheres. The FORTIFIED Roof program, for example, calls for FM 4473 Class 4 on tile roofs.
Run Your Own Drop Test
Choose a hail size. The steel ball drops onto the sample, and the readout shows which UL 2218 class uses a ball that big, the number to check on shingles for storms.
1-Inch Hail
Below the Class 1 ballThe NWS severe threshold. It’s smaller than the 1.25-inch Class 1 ball, so every UL 2218 class is tested with a larger ball.
1.25-Inch Hail
UL 2218 Class 1The entry point of the scale. A Class 1 shingle showed no opening on the back after two strikes from this ball.
1.5-Inch Hail
UL 2218 Class 2A step up in energy. Class 2 shingles passed the same double strike with a 1.5-inch ball.
1.75-Inch Hail
UL 2218 Class 3The kind of hail that makes the news. Class 3 shingles passed with a ball this size.
2-Inch Hail
UL 2218 Class 4The top of the scale, and the target for shingles for storms. The FORTIFIED Hail Supplement also aims at hail up to 2 inches.
Simulation, for illustration only. Ball sizes per class: UL 2218 as reported by IBHS. Hail size names: National Weather Service. A rating describes a test result, not any single storm.
The Two Wind Tests and Their Top Classes
Hail gets the headlines, but wind works on a roof more often. Shingles for storms carry a separate wind class from one of two methods. NRCA’s Professional Roofing lists the classes and the wind speeds behind them.
Air is blown across an installed test panel. The classes climb from A at 60 mph to D at 90 mph and F at 110 mph, the top of this scale.
Built for shingles with factory-applied, self-sealing strips. Classes D, G and H map to basic wind speeds of 115, 150 and 190 mph.
The two numbers are measured differently, so don’t compare 110 to 190 head to head; look for the top class in either method on shingles for storms. The FORTIFIED Roof standard accepts either one: asphalt shingles must meet ASTM D3161 Class F or ASTM D7158 Class H. For what Ohio gusts do to a roof in real life, see our report on Dayton Ohio wind damage.
The Results Table for Shingles for Storms
| Protocol | Top result | What it tests | What to ask for |
|---|---|---|---|
| UL 2218 | Class 4 | Steel-ball impact, 1.25″ to 2″ | PASS Class 4 on the product listing |
| FM 4473 | Class 4 | Impact from ice spheres | Common on tile and other hard roofs |
| ASTM D3161 | Class F | Fan-induced wind, up to 110 mph | PASS Class F on the wrapper |
| ASTM D7158 | Class H | Uplift on sealed shingles, 190 mph basic wind speed | PASS Class H on the wrapper |
| IBHS FORTIFIED Roof | Designation | The whole roof system, deck to edges | An evaluator-verified install, plus the optional Hail Supplement |
Reading the table: the first four rows rate the product; the last rates the installation. Shingles for storms perform when both halves are right.
Testing the Whole Roof, Not Just the Shingle
Even top-rated shingles for storms rely on what’s under them. The FORTIFIED Roof standard from IBHS applies that thinking to the whole roof. These are the line items it checks:
- Sealed roof deckSeams sealed so water can’t pour in if the covering is lost.CHECK 1
- Ring-shank nailsSet in an enhanced pattern to hold the deck in high wind.CHECK 2
- Stronger edgesA wider drip edge and a fully adhered starter strip.CHECK 3
- Wind-rated shinglesASTM D3161 Class F or ASTM D7158 Class H.CHECK 4
- Hail Supplement (optional)Shingles rated Good or Excellent on the IBHS hail impact ratings.CHECK 5
Nails Change the Numbers
IBHS testing found that 8d ring-shank nails at closer spacing can double the uplift a roof deck withstands. A storm rating starts at the nail.
GAF Shingles on the Test Bench
Here’s how two GAF shingles for storms line up against the tests above, in GAF’s own words.
Timberline HDZ® with LayerLock®
GAF says its patented LayerLock® Technology powers the StrikeZone® nailing area, which it calls “the industry’s widest nailing area.” Shingles with LayerLock® can qualify for the WindProven™ Limited Wind Warranty, which GAF describes as having “no maximum wind speed limitation.”
It applies with qualifying GAF accessories: starter strips, Roof Deck Protection, ridge caps, and leak barrier or attic ventilation. GAF lists a 15-year term.
✓WindProven™ eligibleTimberline AS II®
According to GAF, Timberline AS II “passes UL 2218 Impact-Resistance Test with Class 4 Rating (highest possible).” It’s made with what GAF calls “rubber-like SBS modified asphalt.” GAF also lists it as WindProven™ eligible with the required accessories.
✓UL 2218 Class 4
A rating is earned in the lab. It’s kept on the roof by the crew that installs it.
Labs test shingles for storms on properly built decks, so the install has to match. A shingle roof has seven components: leak barrier, underlayment, starter strip, shingles, flashing with drip edge, hip and ridge cap, and attic ventilation. Our breakdown of roofing system components explains each. Weighing shingles for storms against metal or slate? Our guide to durable roofing material compares the options.
GAF also notes potential insurance savings with Class 4 shingles, so ask your agent what your policy offers.
The Takeaway Worth Sharing
Every storm rating is a crash test you can read. Check the impact class, check the wind class, then check who’s installing the system.
Send this to the neighbor comparing shingle samples after the last hailstorm.
CERTIFIED READReady to Put a Rated Roof on Your House?
Thrush & Son®: family-owned roofing and exterior pros since 1960.
We install GAF Timberline HDZ, UHDZ, AS II, Camelot II and Slateline shingles for storms across the Miami Valley. For the local side of this story, read the Thrush & Son® guide to GAF storm-rated shingles, then book a roof assessment.
➡️ Schedule in Dayton➡️ View All ServicesCall (937) 833-5136 · 115 Jefferson St, Brookville, OH 45309
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Further Reading
Official sources: the Insurance Institute for Business & Home Safety, IBHS FORTIFIED, the National Weather Service and NRCA’s Professional Roofing.
Shingles for Storms FAQ
What ratings should I look for in shingles for storms?
Look for two ratings on the same shingle: UL 2218 Class 4 for impact, and ASTM D3161 Class F or ASTM D7158 Class H for wind. Those are the top classes in each test.
How does the UL 2218 hail test work?
Steel balls from 1.25 to 2 inches are dropped onto installed shingles, with two strikes at each spot. The shingle passes if no opening shows on the back. Passing with the 2-inch ball earns Class 4.
What is the difference between Class F and Class H wind ratings?
Class F is the top result in ASTM D3161, a fan-induced test, at 110 mph. Class H is the top result in ASTM D7158, an uplift test for self-sealing shingles, at a 190 mph basic wind speed.
Is a Class 4 shingle the same as a FORTIFIED Roof?
No. Class 4 rates the shingle. A FORTIFIED Roof from IBHS covers the whole system, including a sealed roof deck, ring-shank nails, stronger edges and wind-rated shingles.
Can impact-rated shingles lower my insurance premium?
It depends on your insurer. GAF notes potential insurance savings with Class 4 shingles, so ask your agent what your policy offers before you choose.
Written by Corey Thrush, Vice President and third generation of Thrush & Son®.
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