How adjusters score hail damage: the test square
The industry-standard method for evaluating hail damage on an asphalt-shingle roof is the 10x10 test square. Here's how it works:
- The adjuster (or roofer, or public adjuster) marks a 10-foot by 10-foot section on each slope of the roof with chalk.
- They count the number of confirmed hail impacts within that square — circular bruises where granules have been displaced and the underlying asphalt mat shows damage.
- Each carrier has an internal threshold for what counts as a "totaled" slope. Common thresholds in Iowa run 8-10 hits per test square, though specific carriers vary.
- If the threshold is met on multiple slopes, the carrier typically approves full replacement. If only one or two slopes meet threshold, partial replacement may be offered.
The square gets photographed. Hits get circled with chalk. The adjuster documents date, time, weather data (NOAA storm reports), and the underlying shingle condition.
Functional vs cosmetic damage
This distinction matters for whether your claim is paid:
Functional damage
Damage that compromises the shingle's ability to do its job — keep water out, protect the substrate, last to its rated lifespan. Functional damage includes:
- Bruising of the asphalt mat. A dark, soft spot under the granules. Cracked the shingle's fiberglass mat.
- Granule displacement exposing the asphalt. Granules protect the asphalt from UV. Once exposed, the asphalt degrades quickly.
- Fractured or punctured shingles. Larger hail can crack shingles outright.
- Damaged metal flashing, vents, ridge cap. If hail dented metal flashing or fractured ridge cap shingles, water entry is more likely.
Functional damage is typically covered under Iowa hail policies.
Cosmetic damage
Damage that affects appearance but doesn't compromise function:
- Small granule loss that doesn't expose the mat.
- Surface marks visible only at close range.
- Minor dents in metal that don't affect water-shedding.
Partial vs full replacement
If only one or two slopes meet the carrier's damage threshold, the adjuster may approve partial replacement. The trade-offs:
Why partial can be a problem
- Matching. New shingles rarely match weathered shingles. Your roof becomes two-tone.
- Mixed lifespan. The new slopes will outlast the older slopes, often by years. You'll re-claim or pay cash later.
- Manufacturer warranty issues. Some manufacturers won't warranty partial installations.
- Resale. A buyer's inspector will flag a two-tone roof as a concern.
The Iowa matching-statute reality
Iowa does not have a statewide matching statute that requires carriers to replace undamaged slopes for cosmetic uniformity. Some states do; Iowa doesn't. That said, certain Iowa case law has supported full replacement when partial would result in "an aesthetically and functionally non-uniform roof." This is fact-specific and a public adjuster or attorney can advise on your specific claim.
Post-storm inspection checklist
After any storm with marble-size (3/4") or larger hail, walk your property and check:
- Gutters and downspouts. Look for dents, especially on the upward-facing surfaces. Hail dents are round and consistent in size; bird strikes are random.
- Gutter aprons and drip edge. Dents on metal flashing visible from a ladder.
- Air conditioner condenser fins. Bent fins on the top surface are a clear hail indicator.
- Mailbox, garage door, exterior light fixtures. Dents that weren't there yesterday.
- Vinyl siding. Cracks, especially on the storm-facing side of the house.
- Window screens. Tears or impact marks.
- Wood deck. Round dents in soft wood like cedar or pine.
- Painted surfaces. Chipped paint on the storm-facing side.
- Vehicles parked outside. Hail damage on a car is strong evidence the roof was hit.
- Roof shingles (from the ground or with binoculars). Look for circular dark spots, granules in the gutters, missing or fractured shingles.
If you see damage in three or more of the above, file a claim and get a roofer up there. Don't wait — most policies require prompt notice and have a 1-year filing deadline from the date of loss.
Roof types and Iowa hail
| Roof material | Hail performance | Note for Iowa |
|---|---|---|
| 3-tab asphalt | Poor | Damaged easily; mostly phased out on new builds |
| 30-year architectural asphalt | Moderate | Standard corridor product; commonly claimed after storms |
| Class 4 impact-resistant asphalt | Good | Insurance premium discount available; recommended after first hail claim |
| Stone-coated steel | Very good | Holds up well; cosmetic dents possible but rarely functional |
| Standing seam metal | Excellent functional, variable cosmetic | Almost never leaks from hail; cosmetic dents may be excluded |
Iowa hail storm season at a glance
- March-April: Early season. Smaller hail more common.
- May-July: Peak. Most large-hail events occur here. Most claims filed in this window.
- August: Late-season storms still possible.
- September-October: Hail rare but possible with cold fronts.
- November-February: Hail essentially zero. Ice storms and snow load become the winter concern. See winter prep.
Related
See the corridor roofer directory, how to file a hail claim, roof inspection, roof replacement cost, and the shingles vs metal comparison. For broader insurance context, see homeowners insurance. For unresolved hail claims involving bad-faith carrier conduct, our sister site coralvillelaw.com covers Iowa insurance bad-faith law.
Frequently asked
How do adjusters score hail damage?
10x10 test square on each slope. Count hits within the square. Carrier threshold (commonly 8-10 hits) determines whether the slope qualifies for replacement.
Functional vs cosmetic damage — what's the difference?
Functional damage compromises water-shedding (bruised mat, displaced granules exposing asphalt, fractures). Cosmetic damage affects appearance only. Functional is typically covered; cosmetic exclusions are common on metal and some upgraded asphalts.
Can I get a partial roof replacement?
Sometimes yes, when only one or two slopes are damaged. Downsides: matching issues, mixed lifespan, warranty implications, resale concerns. Iowa has no matching statute, but case law sometimes supports full replacement.
How do I know if my roof was hit?
Dents in gutters, AC fins, mailbox, vinyl siding, garage door. Granules in gutters. From the roof: round dark bruise spots, fractured shingles, exposed asphalt.
How long do I have to file an Iowa hail claim?
Most Iowa policies require notice within 1 year of damage; many require "prompt" notice. File as soon as damage is confirmed. The underlying statute of limitations on a breach-of-policy suit is 10 years for written contracts, but policy notice runs first.