Illinois Roofing License IDFPR #19HC00108700 · GAF Certified Contractor
Class 4 impact-resistant shingles cost a few hundred dollars more upfront than standard architectural shingles, and in Illinois – where hail is part of the weather pattern – they usually pay that back via your homeowner insurance discount in 3-7 years. Here’s what Class 4 actually is, how the UL 2218 test works, what discount you’ll see from State Farm / Allstate / Farmers / American Family, and the simple math on whether they pencil out for your home.
What “Class 4” actually means
The Class 4 designation comes from UL 2218 – a standardized impact-resistance test where steel balls are dropped onto a shingle from a fixed height. The shingle is then inspected for cracks in the underlying mat:
- Class 1: 1.25″ steel ball (about marble size)
- Class 2: 1.5″ steel ball
- Class 3: 1.75″ steel ball
- Class 4: 2.0″ steel ball (golf ball size)
To pass Class 4, the shingle has to survive two strikes from a 2-inch steel ball in the same spot without the mat cracking. That’s hail-event level impact.
Class 4 shingles look identical to standard architectural shingles on the roof. The difference is in the asphalt – it’s modified with polymers (typically SBS rubber, sometimes APP plastomer) that make the shingle flexible enough to absorb impact without cracking.
Why this matters in Illinois
The Riverbend, Madison County, and most of central/southern Illinois sit inside what NOAA classifies as a “hail alley” – the broad zone from Texas through the Plains into the Midwest where hail-producing storms are most frequent. Madison County averages 2-4 measurable hail events per year, with the major events (1.5″+ hailstones) hitting every 3-5 years.
Standard architectural shingles handle small hail (under 1″) without lasting damage. What does damage them:
- Hail 1.25″ and larger – bruises the asphalt mat at impact points, knocks granules off, and shortens shingle life. Damage often doesn’t leak immediately – it sits for 6-18 months before water finds the bruised spots.
- Hail 1.5″ and larger – usually triggers an insurance claim. Standard architectural shingles often need replacement after this size event.
Class 4 shingles, in independent testing and real-world Illinois data, hold up substantially better. They still bruise at very large hail (2″+) but resist the small-to-medium hail that damages standard architectural.
The Illinois insurance discount
This is where Class 4 actually pays for itself. Major IL homeowner carriers offer a “impact-resistant roof” discount when you install certified Class 4 shingles:
| Carrier | Typical IL discount |
|---|---|
| State Farm | 5-15% on homeowner premium (varies by ZIP) |
| Allstate | 5-25% (“Impact-Resistant Roofing” discount) |
| Farmers | Available; discount % varies |
| American Family | Class 4 hail discount in most IL counties |
| Liberty Mutual / Safeco | Available where filed |
| Travelers | Up to 5% discount available |
To claim the discount you submit to your carrier:
- A manufacturer certification that the installed product is UL 2218 Class 4 (we provide this)
- An invoice from your roofing contractor confirming the install
- Sometimes photos or a roof inspection
The discount typically applies to your next renewal cycle and continues every year the roof is in service.
The math – does Class 4 pay back?
The cost premium for Class 4 over standard architectural averages $0.50-$0.85 per square foot installed. For typical Riverbend home roof sizes:
- 1,500 sq ft roof: $750-$1,275 premium
- 2,000 sq ft roof: $1,000-$1,700 premium
- 2,500 sq ft roof: $1,250-$2,125 premium
- 3,000 sq ft roof: $1,500-$2,550 premium
Average IL homeowner insurance premium is approximately $1,800-$2,400 per year. With a 10% Class 4 discount (a reasonable midpoint):
- Annual savings: $180-$240
- Payback on a $1,500 premium: 6-8 years
- Payback on a $2,000 premium: 8-11 years
Most homeowners stay in their home for 12-15+ years. If you’re planning to be in the house longer than ~7 years, Class 4 essentially pays for itself before you sell. After that, it’s a free hedge against the next hail event you’ll have to claim.
If you’re moving in 3-4 years, the math is less clear unless your specific carrier offers a larger discount. Get an actual quote from your agent before making the call.
Class 4 product lines we install
Trill Roofing installs these Class 4 lines:
- GAF Timberline AS II – the impact-resistant version of GAF’s most-installed line. Uses GAF’s StrikeZone technology with SBS-modified asphalt. As a GAF Certified Contractor we can register the System Plus extended warranty on this line.
- CertainTeed Landmark IR / NorthGate – Landmark architectural style with the Atlas FlexSEAL SBS-modified core.
- Owens Corning Duration STORM – uses OC’s SureNail strip plus SBS modification.
- Atlas StormMaster Slate / StormMaster Shake – designer-look impact-resistant lines.
All four are UL 2218 Class 4 rated and all four qualify for IL insurance discounts. The choice between them is usually about color availability, warranty preference, and whether you want the GAF Certified labor warranty backing (only GAF lines).
What Class 4 does NOT do
Two important caveats:
- Class 4 isn’t “hail-proof.” Very large hail (2″+) can still bruise the mat, and any hail event can knock granules loose. Class 4 reduces the likelihood you’ll need a claim – it doesn’t eliminate it.
- The discount doesn’t apply if the contractor isn’t certified to install the product. Some carriers require manufacturer-certified installation (we hold GAF Certified, the highest GAF tier). Confirm your contractor’s certifications before signing.
Talk through your options
If you’re planning a roof replacement in the next year and want to run the Class 4 math against your specific carrier and roof size, schedule a free inspection at /free-inspection/ or call (618) 304-7094. We’ll quote both standard architectural and Class 4 side by side, and you can take both quotes to your insurance agent before deciding.
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