Understanding the Risks for Commercial Properties in Missouri and Illinois
From sudden downpours to windstorms and hail, Midwest weather brings a little bit of everything—often all in one season. And for commercial buildings with flat roofing systems, that kind of unpredictability comes with real consequences.
At Jewett Roofing, we’ve seen firsthand how Missouri weather takes a toll on commercial flat roofs. Here’s how each major weather event can affect your roofing system—and what you can do to minimize long-term damage.
Rain: The Pooling Problem
Flat roofs are designed to drain water efficiently, but prolonged or heavy rain—especially common in Missouri’s storm season—can expose weak spots in that drainage plan.
Common rain-related issues include:
Ponding water due to clogged drains or low spots in insulation
Membrane deterioration from constant moisture exposure
Leaks at seams and penetrations if flashing or seals are aging
Over time, standing water can cause membrane blistering, structural stress, or even roof deck damage—especially on EPDM and older modified bitumen systems.
Wind: Uplift and Edge Failure
Midwestern storms often bring damaging wind gusts, which are particularly hard on flat roofs.
Watch out for:
Membrane uplift, especially on mechanically fastened systems like TPO
Detached flashing and edge metal
Ballast displacement on loose-laid EPDM systems
Wind damage isn’t always immediately visible, but it can leave your roof vulnerable to water intrusion the next time it rains.
Hail: Impact and Hidden Damage
Hailstorms are a recurring threat throughout Missouri and Illinois—and while flat roofing systems are built to take some impact, they’re not invincible.
Hail can cause:
Cracks and bruises in the membrane
Damage to insulation layers beneath the surface
Punctures at seams or fastener points
The challenge with hail damage is that it often goes unnoticed until leaks develop weeks or months later. That’s why post-storm inspections are so important.
Snow and Ice: Freeze-Thaw Cycles Add Stress
While summer storms get the most attention, Midwest winters come with their own risks.
Flat roofs are particularly susceptible to:
Ice dams, which trap meltwater and push it under seams
Added weight from snow accumulation
Membrane cracking from freeze-thaw expansion
This is especially true for aging EPDM systems or roofs with poor slope and drainage design.
Local Climate, Local Expertise
In places like St. Louis, MO and Greenville, IL, commercial roofs need to be built and maintained with local weather in mind. At Jewett Roofing, we specialize in roofing systems that are engineered for the region’s seasonal extremes—and we know what to look for when damage occurs.
Protect Your Roof from the Next Storm
The best way to prepare for severe weather is through proactive maintenance and professional inspections—especially after a major weather event.
If your roof has been through one of this season’s storms, don’t assume it’s fine because you don’t see water coming in yet.
Schedule an inspection with Jewett Roofing to get peace of mind—and a clear plan for protecting your investment.
