Class 4 is the highest impact rating a roof covering can earn. Many Colorado insurers give a premium credit for it, and a 2026 state law adds roof grants starting in 2027.
What "Class 4" means
Impact ratings come from the UL 2218 test. Steel balls are dropped on installed roofing, and the size of the ball sets the class: 1.25 inches for Class 1 up to 2 inches for Class 4. For Class 4, a 2-inch steel ball is dropped twice from 20 feet onto the same spot, and the roofing passes only if it shows no cracks or ruptures.
Class 4 shingles are usually made with rubberized (SBS-modified) asphalt or a reinforced mat, so they flex instead of cracking. You'll also find Class 4 metal, synthetic shake and synthetic slate.
A Class 4 rating means the product passed a lab test. It doesn't mean it can't be damaged. Hail larger than 2 inches, or wind-driven hail, can still damage a Class 4 roof, and most manufacturers don't warrant shingles against hail.
How the insurance discount works
Many Colorado insurers offer a credit on your homeowners premium for an impact-resistant roof. The amount varies by company and location, and it usually doesn't happen automatically.
- Call your agent before you choose a shingle. Ask whether they give a credit, which products qualify, and what proof they need.
- Get the paperwork at install. Most insurers want an invoice naming the exact product line and its Class 4 rating, and some want a certificate from the roofer or manufacturer.
- Send it in and confirm. Check that the credit shows up on your next renewal.
Ask one more question: does the policy have a cosmetic damage exclusion? Some insurers pair impact-resistant roofs, especially metal, with an exclusion for dents that don't cause leaks. Know what you're trading before you sign.
Upgrading during an insurance claim
If hail totals your standard shingle roof, your insurer pays to replace it with like kind and quality, which means standard shingles. You can upgrade to Class 4 and pay the difference yourself. The upgrade has to be shown honestly on the contract and invoice. It can't be folded into the insurance estimate.
Colorado's new roof grant law (SB26-155)
Governor Polis signed SB26-155 on June 4, 2026. It creates the Strengthen Colorado Homes Enterprise inside the Colorado Division of Insurance to give homeowners grants to retrofit their homes with resilient roofs that stand up to wind and hail.
- Starting in 2027, insurers pay a fee of 0.5% of prior-year homeowners premiums to fund the grants, and they can't add it to your bill.
- Insurers must show in their rate filings that savings from resilient roofs are passed through to homeowners.
- A seven-member board will set grant amounts and which roofs qualify. Those details weren't public as of October 2026.
If you're planning a new roof in the next year, ask us about Class 4 options, and watch for the program's application rules in 2027.
Class 4 vs. Class A: two different ratings
Class 4 is about hail impact. Class A is about fire. Under Colorado's 2026 wildfire code, homes in mapped wildfire areas need a Class A roof when 25% or more is replaced. Most asphalt shingles are Class A as a system, and many are also Class 4, so one roof can meet both. See our wildfire roofing code guide.
Common questions
Are Class 4 shingles hail-proof?
No. Class 4 means the shingle passed a test with a 2-inch steel ball dropped twice from 20 feet. Larger or wind-driven hail can still damage it, and most manufacturers don't warrant shingles against hail.
Will my insurance discount apply automatically?
Usually not. Ask your agent which products qualify, keep the invoice that names the Class 4 product, and send it to your insurer.
Can insurance pay for a Class 4 upgrade?
Insurance pays for like kind and quality. If you had standard shingles, you pay the difference for Class 4, and it must be shown honestly on your contract.
What is the Strengthen Colorado Homes program?
A grant program created by SB26-155, signed June 4, 2026, to help homeowners install wind- and hail-resistant roofs. Funding starts in 2027, and the program's board will set grant amounts and eligibility.
Sources
- Colorado House Democrats: SB26-155 signed into law (June 4, 2026)
- GAF: What you need to know about impact-resistant shingles
- Cedur: Guide to impact-resistant roofing (UL 2218 classes)
Updated October 9, 2026. This guide is general information for Colorado homeowners, not legal or insurance advice. Your policy's wording controls your coverage, so read it or ask your agent about your specific situation.