Are Class 4 impact resistant shingles worth it on a Plano roof? The label is printed on the bundle, many contractors recommend it, and an insurer may mention a discount. What the label actually proves is narrower than most sales pitches suggest.
This guide explains what the Class 4 rating measures, what the test standards themselves say they do not cover, what independent hail research has found, and how to document the roof so your insurer can decide. It does not quote prices or discount amounts, because those depend on the product, the quote and the insurer.
What does “Class 4” mean on a shingle?
Class 4 is the highest of four impact classes in two laboratory test standards: UL 2218, which drops steel balls on flexible roof coverings such as asphalt shingles, and FM 4473, which fires ice balls at rigid materials such as tile. Class 4 uses the largest projectile, two inches in diameter, in both standards.
The Asphalt Roofing Manufacturers Association (ARMA) summarizes both standards for consumers. It notes that impact resistance is not required by the building codes, and that it is a property many homeowners care about anyway.
The two standards share a four-class structure, but they test different products with different projectiles:
| UL 2218 | FM 4473 | |
|---|---|---|
| Typical products | Flexible coverings: asphalt shingles, metal panels | Rigid coverings: clay tile, concrete tile, slate |
| Projectile | Steel ball, dropped | Freezer ice ball, propelled by a launcher |
| Class 1 size | 1.25 in | 1.25 in |
| Class 2 size | 1.50 in | 1.50 in |
| Class 3 size | 1.75 in | 1.75 in |
| Class 4 size | 2.00 in | 2.00 in |
| Highest rating | Class 4 | Class 4 |
The UL 2218 projectile sizes come from the IBHS report Relative Impact Resistance of Asphalt Shingles, which states that the steel balls are dropped from the height needed to match the kinetic energy of a hailstone of the same size. The FM 4473 sizes come from the FM Approvals 4473 test standard, section 2.1.
How does the UL 2218 test work?
UL 2218 drops steel balls of four sizes onto a test deck of shingles and then examines the impact points. ARMA describes drop heights from 12 to 20 feet. A shingle earns Class 4 if it withstands the two inch ball without the kind of damage the standard counts as a failure.
The standard’s own scope, published on the UL Standards and Engagement page for UL 2218, adds detail that rarely appears in marketing:
- It targets weak points. The steel ball strikes locations chosen to be most vulnerable, such as edges, corners, unsupported sections and joints.
- It tests new material. The scope states that the method does not evaluate weathering, temperature, aging or similar effects on impact resistance.
- Installation matters. The scope lists time, roof slope, roof system configuration and application among the factors that influence field performance and that the test does not address.
- Steel is not hail. The scope states there is no currently established direct correlation between performance under hailstones and performance under steel balls.
The current edition is Edition 2, ANSI approved on May 28, 2024, according to the same page.
The IBHS report explains what counts as a pass. Any opening on the back of the shingle, such as a tear, crack or rupture, is a failure. Crushed or dislodged granules, dents, and openings visible only on top are not failures. A Class 4 shingle can dent or lose granules in the test and still pass.
How is FM 4473 different?
FM 4473 is the FM Approvals standard for rigid roofing such as slate, concrete and clay. It uses ice balls frozen from distilled water and launched at set kinetic energies, rather than dropped steel. To pass, a specimen must show no visible cracking or breakage after impact.
The FM 4473 standard explains why it uses ice. It describes ice balls as the nearest hailstone approximation known when it was written, and notes they are generally harder and denser than hailstones, so they simulate a worst case hailstone.
Three other points in the standard are useful for a homeowner reading a tile quote:
- New material only. Section 1.2.4 states that long exposure to the elements can significantly lower the hail resistance of roof materials, and that the standard is for new rigid roof covers.
- A test is not an approval. Section 1.3.2 states that meeting the test requirements does not by itself qualify a product for FM Approval.
- Marking. Section 6 requires the packaging and the product to show the manufacturer’s name, the product trade name, and the FM Approvals Hail Impact Resistance Classification.
Are Class 4 impact resistant shingles worth it, based on the research?
Independent testing supports a qualified yes: Class 4 shingles generally did better than basic shingles in IBHS lab tests, but none performed perfectly, and performance varied by product and declined with age. Whether that is worth it for your home depends on the product chosen and what your insurer offers.
The Insurance Institute for Business and Home Safety (IBHS) runs its own hail laboratory. Its 2014 report tested 22 asphalt shingle products from five manufacturers under UL 2218. Its findings include:
- Shingles rated Class 4 should, in theory, survive all four ball sizes. In practice, none of the products tested, basic or impact rated, passed more than Class 2 impacts without at least one location failing.
- At Class 4 impacts, the impact rated architectural shingles passed at about 40 percent of locations, against about 30 percent for basic architectural shingles.
- Polymer modified impact rated shingles passed at about 55 percent of locations at Class 4 impacts, against about 35 percent for traditional impact rated shingles.
- Premium architectural shingles that were not impact rated did better than basic shingles but worse than impact rated ones in all four classes.
The shingles were bought from local vendors in 2013, so these results describe those products, not the ones on sale today.
IBHS later developed the IBHS Impact Resistance Test Protocol for Asphalt Shingles, which uses laboratory made hailstones rather than steel balls. IBHS says the protocol rates relative performance for dents, tears and granule loss, rather than giving a pass or fail.
IBHS states that the protocol is designed for research and product comparison only. It is not intended for insurance claims handling, product warranties or legal standards. That is worth remembering if anyone presents an IBHS score as a guarantee.
What are the IBHS shingle ratings?
IBHS publishes hail impact-resistant shingle ratings that compare impact rated asphalt shingles bought from retail stores. The ratings score products on dents, tears and granule loss. IBHS says not all impact resistant shingles perform the same, and suggests asking your roofer about the data.
If a quote names a specific shingle line, look it up in the IBHS ratings before you sign. The Class 4 label says it passed UL 2218; the IBHS rating says how it compared with other impact rated products.
The IBHS FORTIFIED Home Hail Supplement (2020) shows how the two fit together. For asphalt shingles it requires an IBHS rating of Good or Excellent. For shingles IBHS has not yet tested, it accepts documentation that the product is polymer modified and holds a UL 2218 Class 4 or FM 4473 Class 4 rating. Clay and concrete tiles must meet FM 4473 Class 4, and metal must meet UL 2218 Class 4.
Does a Class 4 roof stop hail damage?
No. A Class 4 rating describes how new material performed in a lab, and both the standards and IBHS research say aging and repeated hail reduce that performance. Granule loss and dents are not failures under UL 2218, and metal can dent visibly while still working.
Three IBHS findings explain why:
- Age reduces performance. The IBHS short-term roof aging farm reports that early testing shows natural short-term weathering can measurably reduce hail impact performance, and that repeated hail exposure can accelerate that decline.
- Small hail adds up. IBHS research on high concentrations of small hail found that roofs exposed to weathering and two simulated small hail events became up to ten times more susceptible to damage from later large hail than new shingles. IBHS adds that current testing standards do not assess durability over time.
- Metal dents. The FORTIFIED Hail Supplement notes that impact rated metal roofs are likely to survive most hail without functional damage, but can show permanent dents.
Hail is not rare here. NOAA Storm Events data for the Plano area record 310 hail reports on 62 days from 2016 through 2025, including 63 reports of hail two inches or larger on 17 days. Those are report counts, not a full record of every storm. For how material and age shape a roof’s working life, see our guide to how long a roof lasts in North Texas.
Will a Class 4 roof lower your insurance premium in Texas?
It might. The Texas Department of Insurance says your insurance company might give you a discount for roofing materials less likely to be damaged by wind, hail or fire, and that each company decides what discounts it offers and how much. Ask your own insurer before you choose a product.
TDI’s page on replacing your roof gives that advice in one line. Its homeowners insurance guide lists an impact resistant roof among the features that might earn a discount, alongside monitored alarms, sprinklers, a newer home, bundled policies and a claim free record.
The TDI pages cited here give no discount amount. Treat any percentage in a sales pitch as a claim to verify with your insurer, not a promise. Questions worth asking your agent before the roof goes on:
- Do you offer a discount for an impact resistant roof, and on which part of the premium?
- Which rating do you accept: UL 2218 Class 4, FM 4473 Class 4, or something else?
- What documents do you need, and when do you need them?
- Does the roof need an inspection before the discount applies?
- Does a Class 4 roof change how a hail claim is settled, for example on cosmetic damage?
The last question matters because policy terms, not the shingle, decide what a claim pays. TDI also advises asking whether your wind and hail deductible differs from other deductibles. Our guide to wind and hail deductibles in Texas explains how those work.
How do you prove you have a Class 4 roof?
Proof means documents that tie a specific rated product to your address. Keep the product name, the rating standard and class, and evidence that this product was installed on this roof. Your insurer decides what it will accept, so ask before the job starts.
A practical record set looks like this:
| Document | What it shows | Where it comes from |
|---|---|---|
| Itemized contract or invoice | The exact shingle line installed at your address | Your roofing contractor |
| Product data sheet | The UL 2218 or FM 4473 class claimed | The manufacturer |
| Bundle wrapper photo | The marked product and rating on the packaging | Taken on site during the job |
| Dated job photos | The product going onto your roof | Taken on site during the job |
| Insurer’s own form, if any | The format your insurer requires | Your insurer or agent |
Wrapper photos help because FM 4473 requires its classification on the packaging, and ARMA notes that manufacturers list test standards on packaging. Keep these records with your policy file.
What affects the cost of a Class 4 roof?
The price difference depends on the product line, the roof and the contractor, so this guide does not quote figures. Compare like with like: the same roof area, the same scope of tear off and underlayment, and a named Class 4 product against a named standard one.
When you read two quotes, check these points:
- The named product. “Class 4 shingle” is not a product. Ask for the manufacturer and line, then look it up in the IBHS ratings.
- The rating claimed. Confirm UL 2218 Class 4 for shingles or metal, or FM 4473 Class 4 for tile.
- Everything else in the scope. Decking, underlayment, flashing and ventilation affect performance too, as the UL 2218 scope itself acknowledges.
Then weigh the quote against what your insurer confirms in writing, if anything. For help weighing replacement against other options, see our guide to protecting a Plano home from hail. Roofing Repair Plano can quote both standard and Class 4 options through our roof replacement service.
Frequently asked questions
Are Class 4 impact resistant shingles worth it in Plano?
They can be. IBHS lab testing found impact rated shingles generally outperformed basic shingles, though none were perfect and aging reduced performance. The value for you depends on the specific product, its IBHS rating if tested, and whether your insurer confirms a discount. Ask your insurer before choosing.
What is the difference between Class 3 and Class 4 shingles?
The difference is the projectile size in the UL 2218 test. Class 3 uses a 1.75 inch steel ball and Class 4 uses a 2.00 inch ball, the largest size. FM 4473 uses the same four sizes with ice balls for rigid materials such as tile. Class 4 is the highest rating in both.
Do Class 4 shingles prevent all hail damage?
No. UL 2218 does not count granule loss or dents as failures, and it tests only new material. IBHS research found that weathering and repeated small hail reduce hail resistance over time. A Class 4 roof can still be damaged, and your policy terms decide what a claim pays.
How do I know if my shingles are impact resistant?
Check your roofing contract or invoice for the exact product line, then read the manufacturer’s data sheet for a UL 2218 or FM 4473 class. FM 4473 requires its classification on the packaging. If you have no records, ask a roofer to identify the product during an inspection.
Does Texas require insurers to give a Class 4 discount?
TDI says only that an insurance company might give you a discount for materials less likely to be damaged by hail, and that each company decides what discounts to offer and how much. Its consumer pages give no amount, so ask your own insurer what it offers.
