When severe weather hits the Midwest, your commercial roof takes the brunt of it. Strong winds, large hail, and heavy rain can cause damage that isn’t always visible right away—but can still void warranties, cause long-term problems, and lead to expensive repairs down the road.
Knowing what to look for after a storm—and when to take action—can make all the difference. Here’s what every building owner should understand about storm damage thresholds.
The Numbers That Matter
Not all storms are created equal, and neither is the damage they cause. Here are the critical thresholds that often spell trouble for commercial roofing systems:
Wind Gusts Over 55 MPH:
Most commercial roofing systems are only rated to withstand wind speeds up to 55 miles per hour. Once gusts exceed that threshold, there’s a real risk of membrane uplift, flashing separation, or even full sections of roofing being torn off.Hail 1.5 Inches or Larger:
Hail damage becomes a serious concern at 1.5 inches in diameter—the minimum size most insurance companies require to qualify for storm-related claims. At 2 inches or more, damage is almost guaranteed, especially to single-ply systems like EPDM or TPO.
Even if your roof appears intact from the ground, damage to the membrane, insulation, or seams can compromise the system—and go unnoticed until a leak shows up weeks or months later.
Why Interior Leaks Aren’t the First Sign
One of the biggest misconceptions we see is the idea that “if it’s not leaking, it’s fine.” Unfortunately, that’s not always the case.
Commercial roofing systems are made up of multiple layers. Water can enter through a puncture or seam separation and saturate insulation or decking long before it ever shows up inside. By the time you see a water stain on a ceiling, the underlying issue may have already gotten worse—and more expensive to fix.
What to Do After the Storm Passes
If your area experienced high winds or large hail, don’t wait for leaks to appear. Here’s what we recommend:
Check for Visible Signs of Damage:
Look around the property for torn membrane, debris, or roofing material on the ground. Dents in rooftop equipment or flashing can also indicate hail impact.Take Photos for Documentation:
Even if you’re not filing an insurance claim, having dated photos of the damage can help with warranty claims or future planning.Schedule a Professional Roof Inspection:
A quick inspection by the Jewett Roofing team can reveal hidden damage and help you determine whether spot repairs, a full restoration, or an insurance claim is appropriate. We’ll also help document everything for your records and provide detailed repair options.
Protect Your Warranty—and Your Investment
Most manufacturers require inspections after major weather events to keep your warranty intact. If your roof has been exposed to wind gusts above 55 mph or hail over 1.5″, we recommend having it inspected—whether or not you see immediate issues.
At Jewett Roofing, we’re here to help building owners in the Greater St. Louis and Greenville areas respond quickly after storms. With decades of experience and a fast response team, we can assess, document, and repair storm damage with minimal disruption to your operations.
Storm season doesn’t have to catch you off guard.
If your facility has been impacted by recent weather, contact Jewett Roofing today to schedule a post-storm inspection.
