Not every storm is worth driving to. Not every hail event turns into a roof replacement. And not every roof replacement turns into a paid insurance claim. The contractors and adjusters who make the most money in storm restoration are not the ones who chase every weather alert — they are the ones who know exactly which combination of storm severity, hail size, wind speed, and roof type produces a claimable loss. This guide breaks down every variable so you can make that call before you ever leave the driveway.
The Hail Size Threshold That Actually Matters
Hail size is measured in diameter and reported in inches by NOAA storm spotters. The most commonly cited threshold in the roofing industry is one inch — roughly the size of a quarter — because that is the minimum size at which most insurance carriers will consider a functional damage claim on a standard three-tab or architectural shingle roof. But one inch is the floor, not the target.
| Size | Diameter | Reference | Damage Profile |
|---|---|---|---|
| 0.75" | ¾ inch | Penny | Cosmetic only. Granule loss on soft metals. Rarely claimable on shingles. |
| 1.00" | 1 inch | Quarter | Functional damage threshold. Bruising on standard shingles. Most carriers open a claim file. |
| 1.25" | 1¼ inch | Half dollar | Clear functional damage. Granule loss, mat exposure. Strong claim basis on most roof types. |
| 1.50" | 1½ inch | Ping-pong ball | Reliable full replacement territory. Damage visible on inspection. High claim approval rate. |
| 1.75" | 1¾ inch | Golf ball | Significant structural damage. Cracked shingles, dented ridge caps, gutters deformed. Near-certain replacement. |
| 2.00" | 2 inch | Hen egg | Severe. Punctures on older roofs. Extensive metal damage. High-value claims. |
| 2.75"+ | 2¾ inch+ | Baseball+ | Catastrophic. Structural deck damage possible. Commercial and residential total loss events. |
The sweet spot for storm chasers is the 1.5-inch to 2-inch range. These events produce widespread, documentable functional damage that clears the insurance threshold on virtually every roof type — but they do not produce the kind of catastrophic structural damage that triggers lengthy engineering reviews and claim disputes.
Wind Speed and What It Does to a Roof
Wind damage is the most underestimated category in storm restoration. Contractors focus on hail because it is dramatic and easy to photograph, but wind damage is often more widespread, affects more properties per event, and is frequently overlooked by homeowners who do not know what to look for.
| Wind Speed | Classification | Roof Damage Profile |
|---|---|---|
| 40–57 mph | Moderate | Lifted shingle tabs, broken seals, granule loss in exposed areas. Claimable on older roofs. |
| 58–74 mph | Severe | Shingle creasing, tab blow-off, exposed underlayment. Claimable on most roofs regardless of age. |
| 75–99 mph | Extreme | Widespread shingle loss, ridge cap failure, potential deck exposure. High-value claims. |
| 100+ mph | Catastrophic | Structural damage. Partial or total roof loss. Engineering review typically required for large claims. |
The critical wind threshold for most insurance policies is 58 mph — the boundary between a moderate and severe wind event. Below 58 mph, carriers often argue that damage is the result of pre-existing wear rather than the storm event. At 58 mph and above, the burden of proof shifts significantly in favor of the claimant.
Understanding Impact-Resistant Shingles: Class 1 Through Class 4
Impact-resistant (IR) shingles are rated under UL 2218, a standard developed by Underwriters Laboratories that tests roofing materials by dropping steel balls of specific sizes onto them from a fixed height and evaluating the result. The ratings run from Class 1 (lowest resistance) to Class 4 (highest resistance), and they have enormous implications for both insurance premiums and claim outcomes.
Class 1 — Baseline Protection
Class 1 shingles pass the UL 2218 test when struck by a 1.25-inch steel ball dropped from 12 feet. Standard three-tab asphalt shingles and most entry-level architectural shingles fall into this category. From a claims perspective, Class 1 shingles are the most favorable for contractors and adjusters. Any hail event at or above 1 inch will typically produce documentable functional damage on a Class 1 roof.
Class 2 — Moderate Resistance
Class 2 shingles survive a 1.5-inch steel ball impact without cracking. They are typically mid-grade architectural shingles with a slightly thicker mat and more flexible polymer content. In the field, Class 2 shingles will show functional damage from hail events at 1.5 inches and above.
Class 3 — Enhanced Resistance
Class 3 shingles pass the test with a 1.75-inch steel ball. These are premium architectural shingles, often marketed under brand names like Owens Corning Duration Storm, GAF Timberline HDZ, or CertainTeed Landmark IR. Class 3 roofs require hail at 1.75 inches or larger to produce reliable functional damage.
Class 4 — Maximum Resistance
Class 4 is the highest UL 2218 rating. Shingles in this category must survive a 2-inch steel ball impact without cracking. They are typically made with a rubberized asphalt compound, a polymer-modified mat, or a steel core. Class 4 shingles are the most challenging from a claims standpoint — carriers often deny replacement claims for events below the 2-inch threshold, arguing the shingles performed as designed.
The Shingle Age Factor
Shingle age is the variable that most dramatically affects claim outcomes. A 15-year-old Class 4 shingle that has lost significant granule coverage will fail at a much lower hail size than a freshly installed Class 4 shingle. The practical implication: when canvassing, prioritize neighborhoods with homes built between 10 and 20 years ago.
Reading the Soft Metals: Your First Indicator
Before you ever get on a roof, the soft metals on the exterior of a home tell you almost everything you need to know about whether a claimable loss exists. Soft metals — aluminum gutters, downspouts, AC condenser fins, painted steel fascia, window screens, and HVAC equipment — are not impact-rated and will show damage from hail events that leave shingles visually intact. They are your first diagnostic tool.
What to look for: circular dents on aluminum gutters and downspouts, each dent corresponding to a hail impact. The density of dents tells you how many impacts per square foot the roof received. The size of the dents tells you the approximate hail diameter.
Combining Storm Data with Field Judgment
Step 1 — Filter by hail size and wind speed. Pull the storm data and identify events with 1.25-inch hail or larger, or 58 mph wind or higher. These are your target events.
Step 2 — Check the roof age of the impact zone. Use county assessor records to identify the construction year of homes in the impact area. Prioritize homes built 10–20 years ago.
Step 3 — Identify the shingle class if possible. Permit records sometimes include roofing material specifications. If you know a neighborhood was re-roofed with Class 4 shingles after a previous storm, you need larger hail to produce a claimable loss there.
Step 4 — Read the soft metals on arrival. Before knocking a single door, drive the neighborhood and look at gutters, downspouts, and AC units. If you see consistent denting patterns, you have physical confirmation of the storm impact.
Step 5 — Document everything. Photograph the soft metal damage, the roof from the ground, and any visible shingle damage before you approach the homeowner.
Using THOR to Filter Before You Drive
THOR Storm Mapper lets you filter every event in the NOAA/SPC database by event type, hail size, wind speed, and severity classification before you ever look at a map. Set your minimum hail size to 1.25 inches and your minimum severity to Moderate, and every event that appears on the map is already pre-qualified as a potential claim. The entire process from storm alert to canvassing list takes under five minutes.
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