When severe storms move through Missouri and Illinois, most attention goes to hail size or rainfall totals. But wind is often the most destructive force acting on a commercial roof — and its damage isn’t always obvious right away.
In many cases, a roof doesn’t fail during the storm. It fails days or even weeks later.
Here’s what wind is actually doing to your commercial roofing system when severe weather hits.
Wind Doesn’t Just Blow — It Lifts
Commercial roofs aren’t simply “covered” structures. They are engineered systems designed to resist uplift pressure.
When wind moves across a flat or low-slope roof, it creates suction — similar to how airplane wings generate lift. As wind speeds increase, pressure changes across the roof surface, especially along edges and corners.
Those perimeter areas experience the highest uplift forces.
If edge metal, coping caps, or membrane attachment points are compromised, the wind begins to:
Loosen fasteners
Flex the membrane
Stress seams
Pull at flashing details
Even if the roof stays in place, the structural stress may already be happening.
The Perimeter Is the Most Vulnerable Zone
Most wind-related roof failures begin at the edges.
Corners experience the strongest uplift pressure. If perimeter metal or termination bars fail, wind can get underneath the membrane and begin peeling it back.
Once wind enters beneath the system, it no longer needs extreme speeds to cause major damage.
This is why many commercial roof blow-offs start at the edge and progress inward.
Wind Can Damage a Roof Without Tearing It Off
Not every storm results in a dramatic membrane failure. In fact, many wind-damaged roofs still look “intact” from the ground.
But hidden issues may include:
Loosened insulation boards
Stressed or separated seams
Lifted flashing around penetrations
Fasteners backing out
Micro-tears in the membrane
These weaknesses often go unnoticed — until the next rain event.
That’s when interior leaks begin.
Why Roofs Often Fail After the Storm Passes
A common misconception is that if a roof survives the storm, it’s fine.
In reality, wind may have already compromised the system.
A small seam separation or lifted edge detail allows water intrusion during the next rainfall. Over time, moisture spreads beneath the membrane, weakening insulation and adhesion.
Weeks later, the building owner sees water inside — and assumes the leak is new.
In truth, the storm damage happened earlier.
What Building Owners in Missouri & Illinois Should Watch For
After high-wind events, it’s important to inspect for:
Loose or displaced edge metal
Visible membrane lifting
Debris impact or punctures
Wrinkling or bubbling along seams
Water stains near perimeter walls
Early detection prevents small wind damage from becoming major roof failure.
Severe Storms Are Inevitable. Roof Failure Isn’t.
Missouri and Illinois sit in active storm corridors. High winds aren’t occasional — they’re seasonal.
Commercial roofing systems must be maintained with wind resistance in mind. That includes secure perimeter attachment, reinforced edge details, and regular post-storm inspections.
At Jewett Roofing, we help building owners identify wind-related vulnerabilities before they lead to emergency repairs.
Because the real damage often starts where you can’t see it.
