Hailstorms are nothing new in the Midwest. But when hail grows to the size of golf balls, baseballs — or even softballs — the damage goes far beyond what’s visible from the ground.
In recent years, record-breaking hail events across Missouri and Illinois have shown just how vulnerable commercial roofing systems can be. Even when a roof looks “mostly fine,” the reality underneath the surface can tell a very different story.
Here’s what softball-size hail actually does to commercial roofs — and why ignoring it can lead to expensive failures months or years later.
A Look at Extreme Midwest Hail Events
The Midwest consistently ranks among the most hail-prone regions in the country. In recent years, storms across Missouri, Illinois, and neighboring states have produced hailstones exceeding four inches in diameter — large enough to shatter windows, dent vehicles, and severely damage roofing systems.
These storms often move quickly, leaving behind damage that isn’t immediately obvious — especially on large, low-slope commercial roofs where impacts are harder to spot without close inspection.
Why Big Hail Is Especially Dangerous for Commercial Roofs
Commercial roofs are designed differently than residential systems. Flat and low-slope roofs rely on membranes, insulation, and secure attachment — all of which can be compromised by extreme hail impact.
Here’s what happens when hail reaches softball size.
1. Membrane Fractures You Can’t See From the Ground
Single-ply membranes like TPO, PVC, and EPDM may not tear open immediately after a hailstorm. Instead, large hailstones can:
Create micro-fractures in the membrane
Compress or crack the material at impact points
Weaken seams and welded areas
These fractures may not leak right away — but over time, thermal movement and weather exposure turn them into active failures.
2. Insulation Damage That Leads to Hidden Moisture
Below the membrane, hail impact can crush roof insulation boards. This causes:
Loss of insulation R-value
Depressions that collect water
Increased stress on the membrane above
Once insulation is compromised, even small amounts of moisture can spread laterally across the roof system — making future repairs more extensive and costly.
3. Punctures Around Roof Penetrations and Edge Details
Softball-size hail often hits hardest where roofing systems are already vulnerable:
Around HVAC curbs and vents
Along flashing and parapet walls
At roof edges and terminations
These areas may show minor cosmetic damage while concealing serious attachment or seal failures underneath.
4. “Cosmetic” Damage That Still Shortens Roof Life
One of the most common misconceptions after a hailstorm is that cosmetic damage doesn’t matter. In reality:
Dents, bruises, and impact marks weaken materials
Accelerated aging reduces roof lifespan
Manufacturer warranties may be affected
What looks minor today can lead to widespread membrane failure years earlier than expected.
Why Post-Hail Inspections Are Critical — Even Without Leaks
Many commercial roof leaks don’t appear until months after a hailstorm. By then, moisture may already be trapped inside the system.
A professional post-storm inspection can identify:
Impact damage not visible from the ground
Compromised insulation
Areas at risk for future leaks
Early documentation is also critical for insurance purposes, helping building owners address damage before it escalates.
The Bottom Line: Big Hail Leaves Bigger Problems Than You Think
Softball-size hail doesn’t just damage roofs — it shortens their lifespan, compromises performance, and creates hidden risks that often go unnoticed until major repairs are required.
If your building was in the path of a recent hailstorm, even if there are no visible leaks, a thorough inspection can make the difference between a manageable repair and a costly roof replacement.
Jewett Roofing works with building owners across Missouri and Illinois to assess hail damage, document findings, and recommend clear next steps — before small impacts turn into major failures.
