Class 3 vs Class 4 shingles: What's the difference?
Last updated · Storm damage & insurance
Short answer: Class 4 shingles pass a more severe impact test than Class 3 under UL 2218 (larger steel ball / higher drop energy). In hail-prone areas they are often specified for durability; some insurers offer documented discounts for impact-resistant roofs — but discount rules are company- and state-specific.
In hail country — Front Range Colorado, North Texas, Kansas, Minnesota, and similar markets — the Class 3 vs Class 4 conversation shows up on almost every asphalt-shingle bid. The classes come from standardized laboratory impact tests. They are useful comparison tools. They are not magic armor.
UL 2218 impact classes (steel ball)
UL 2218, Impact Resistance of Prepared Roof Covering Materials, rates prepared roof coverings Class 1 through Class 4. The test drops a steel sphere onto specimen shingles from prescribed heights. Higher classes correspond to more severe impact energy (larger sphere and/or greater drop height per the standard's class table). Class 4 is the most severe class in UL 2218.
Passing Class 4 means the tested specimens met the standard's pass criteria for that class under laboratory conditions — not that every shingle on every roof will shrug off a severe hailstorm. Real storms vary in stone size, density, wind-driven angle, and temperature (cold shingles can behave differently than warm ones).
FM 4473 (ice ball) — know which listing you have
FM 4473 uses ice balls rather than steel spheres and is referenced for some roof products' impact performance. Insurers and product literature may cite UL 2218, FM 4473, or both. When an agent asks for "impact resistant" proof, ask which standard and class their underwriting guidelines require, then match the ESR/listing or manufacturer certification letter to that request.
What it means in hail areas
IBHS and insurer loss data have driven interest in impact-resistant (IR) roofs because hail is a major source of property loss in the central U.S. Choosing Class 4 (or another insurer-qualified IR product) can reduce the chance of functional damage in ordinary hail events and may help with insurability or credits — but catastrophic hail can still bruise, puncture, or tear IR shingles. Pair product choice with good attic ventilation, correct nailing, and honest damage documentation after storms.
Insurance discounts — only where documented
Do not assume a Class 4 roof automatically lowers your premium. Credits are optional programs offered by individual insurers, often with state-specific forms, inspection affidavits, or product lists.
- Texas: The Texas Department of Insurance (TDI) publishes consumer information on impact-resistant roof credits. Discounts are set company-by-company — TDI does not mandate one statewide percentage. Ask your carrier for its IR credit rules and qualifying product list; get any credit in writing on your declarations or endorsement.
- Colorado: Hail losses are a major Front Range issue. Many carriers offer IR or roof-type credits, sometimes alongside mandatory or optional hail deductibles governed by Colorado law (including statutes addressing hail damage deductibles such as C.R.S. 6-22-105 — confirm current text). Ask your agent which products qualify.
- Minnesota: Insurers in hail-exposed regions commonly file IR discounts; programs and percentages vary. Confirm with your carrier and the Minnesota Commerce Department consumer resources if you need help comparing.
- Kansas: Kansas Insurance Department consumer materials and individual company filings address impact-resistant roofing discounts in hail-prone areas. Again: company-specific, documentation required.
Other states and carriers may offer similar credits. The pattern is the same everywhere: product listing → contractor invoice with brand/model → insurer form or inspection → credit on the policy.
Cost difference
Class 4 laminated shingles typically cost more than comparable non-IR architectural shingles because of modified asphalt formulations and reinforcing designs. Public sources such as IBHS consumer materials have described IR upgrades on the order of roughly several percent of roof replacement cost in researched scenarios (IBHS has cited figures around a ~9% cost increase in some educational materials — treat that as a research benchmark, not a bid for your house). Your actual delta depends on brand, profile, tear-off scope, and local labor. Compare apples-to-apples bids.
Buying checklist
- Ask your insurer for the written IR credit rules and approved product list before you buy.
- Confirm UL 2218 Class 4 (or the exact standard they require) on the product data sheet.
- Install per manufacturer instructions so you do not trade an insurance credit for a voided shingle warranty.
- Keep the packaging label photo, invoice, and warranty registration.
This is general consumer information, not insurance advice. Coverage and discounts depend on your policy and state filings. Local building codes still apply. When you are ready, schedule a free inspection and estimate and bring your insurer's product list to the appointment.
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Frequently asked questions
Is Class 4 hail-proof?
No. Class ratings are laboratory impact tests, not a promise that severe hail will leave zero damage. Large hail can still injure even Class 4 products.
Will my insurer automatically discount Class 4?
Only if your carrier offers a credit and you meet its documentation rules. Texas, Colorado, Minnesota, Kansas, and other hail states have carriers with IR programs — ask your agent and get the credit in writing.
UL 2218 or FM 4473?
UL 2218 is the common steel-ball impact test for prepared roof coverings (Classes 1–4). FM 4473 is an ice-ball impact standard used for some products. Your insurer will say which listing it accepts.
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Sources
- UL 2218 Impact Resistance of Prepared Roof Covering Materials. www.ul.com/
- FM Approvals 4473 (impact resistance using ice balls — product listing context). www.fmapprovals.com/
- TDI: Products qualifying for impact-resistant roofing credits. www.tdi.texas.gov/company/roofing-discounts.html
- IBHS hail / impact-resistant roofing research and consumer materials. ibhs.org/
- IBHS, Hail Impact Performance of Asphalt Shingles (at a glance). ibhs.org/wp-content/uploads/member_docs/ibhs-hail-impact-at-a-glance.pdf
- IBHS, 2025 Impact-Resistant Shingle Ratings release (Nov 19, 2025). ibhs.org/ibhs-news-releases/ibhs-releases-its-most-expansive-impact-resistant-sh
- C.R.S. 6-22-105. colorado.public.law/statutes/crs_6-22-105
Sources checked November 4, 2026. Estimates are not quotes. Roofing, insurance, and legal details vary. Confirm with your contractor, insurer, or attorney.