Can Heavy Snow on a Flat Roof Cause Damage or Problems? 

If you manage or own a commercial building with a flat roof, the first heavy snow of winter probably brings more than just cold air—it brings concern. “Will this much snow cause leaks? Could my roof collapse?” These are smart questions to ask. At Weather Shield Roofing Systems, we’ve been helping businesses protect their commercial roofs from Michigan winters for over 40 years, and we understand how stressful snow buildup can be. 

Let’s break it down simply, so you know what to watch for, when to act, and how to prevent problems before they start. 

Why is snow on a flat roof a bigger issue than on a sloped one?

Unlike pitched roofs, flat commercial roofs don’t allow snow to slide off naturally. That means snow can pile up quickly and stay there for days—or weeks. The longer it sits, the more pressure it puts on your roofing system. 

Snow is also heavier than it looks. Wet, dense snow can weigh up to 20 pounds per cubic foot, and if you get a foot of snow spread across thousands of square feet, your roof could be carrying tens of thousands of pounds. That added load can lead to: 

• Roof stress or sagging 

• Cracks in roofing materials 

• Leaks or water infiltration 

• Structural damage or collapse in extreme cases 

So yes, heavy snow on a flat roof can absolutely cause problems, especially if your roof isn’t well maintained. 

How much snow is too much for a flat roof?

Every roof is different. Factors like your building’s age, roofing materials, structural design, and recent maintenance history all matter. That said, most commercial flat roofs are designed to handle 20–40 pounds per square foot. If the snow is light and fluffy, you might be okay—but wet, packed snow or ice can exceed that limit fast. 

As a general rule of thumb: 

• 4 inches of wet snow = about 5 pounds per square foot 

• 12 inches of wet snow = 15–20 pounds per square foot 

• 6 inches of ice = nearly 30 pounds per square foot 

If you’re getting consistent snowstorms or freezing rain, the risk builds with each layer that doesn’t melt or get removed. 

What are the warning signs of snow-related roof stress?

It’s not always easy to spot trouble from the ground, but here are some signs that snow load may be causing roof damage: 

• Unusual sounds like creaking or popping from the ceiling 

• Visible sagging or deflection in the roof deck 

• Interior leaks or water stains during or after snowfall 

• Cracks in drywall around walls or ceiling joints 

• Doors or windows that suddenly stick or won’t close properly 

If you see any of these red flags, it’s time to act immediately. Emergency roof repair may be needed to avoid worse structural damage.  

Should I remove snow from my commercial roof myself?

It’s a good question—and an important one. We don’t recommend trying to remove snow from your flat roof yourself or having your maintenance team do it unless they’re trained and equipped for it. 

Why? 

Walking on a snow-covered roof is dangerous 

Using the wrong tools can tear or puncture your roofing membrane 

You may cause more damage than the snow itself 

Instead, consider hiring a professional commercial roofing company that understands how to safely remove snow while protecting your roof system. 

How can I prevent snow damage on my flat roof?

Prevention is always more cost-effective than repair. Here’s how to protect your commercial building before snow causes problems: 

Schedule a winter roof inspection

Before winter hits, have a trusted roofing contractor inspect your flat roof. At Weather Shield, we look for weak points, drainage issues, ponding water, and membrane damage—all things snow and ice can make worse. 

Keep drains and gutters clear

Flat roofs often have internal drains. If those are clogged with debris, melting snow won’t have anywhere to go. That leads to ponding water and increases the risk of leaks or freeze/thaw damage. 

Sign up for a snow removal plan

A proactive snow management plan ensures your roof is monitored and cleared safely when snow loads get risky. Our Max Life Roof Care program includes winter checks and snow removal services tailored to your roof’s needs. 

Repair minor issues before winter

That small blister or split in your membrane? Snow and ice will make it worse. Don’t wait. Address small repairs before the cold makes them bigger (and more expensive) problems. 

What happens if snow melts and refreezes on a flat roof?

This is a common issue with flat commercial roofs in colder climates. During the day, sun or heating may melt some of the snow. But at night, it refreezes—often into heavy ice. This cycle can cause: 

• Freeze/thaw damage to the membrane or flashing 

• Ice dams that prevent drainage 

• Trapped water that eventually seeps into seams or penetrations 

This is why proper drainage and regular winter roof inspections are so critical. 

Is snow damage covered by insurance?

It depends on your policy. Many commercial property insurance policies do cover sudden roof collapses or storm-related damage—but they may deny claims for issues caused by lack of maintenance.

For example, if your flat roof collapses under snow but you haven’t had it inspected or maintained in years, your insurer might argue it was preventable. This is another reason why proactive care, like our Max Life Roof Care program, helps protect not just your roof—but your investment. 

How does a flat roof inspection help in winter?

A professional inspection before and during winter helps you: 

• Understand how much snow your roof can handle 

• Catch and fix small vulnerabilities before they become leaks 

• Ensure your drains, scuppers, and gutters are winter-ready 

• Create a snow load management plan for your specific building 

At Weather Shield Roofing Systems, our commercial roof inspections are detailed, photo-documented, and focused on extending the life of your roof while preventing costly surprises. 

Bottom line: Should I be worried about heavy snow on my flat roof?

If your roof is well-maintained, has proper drainage, and is inspected regularly, you may not need to worry about every snowfall. But ignoring snow accumulation—especially after major storms—can absolutely lead to damage, roof leaks, and costly repairs. 

Weather Shield Roofing Systems has been helping Michigan businesses through tough winters since 1980. If you’re unsure whether your flat roof is ready for the snow season, we’re here to help with honest advice, expert inspections, and snow load management tailored to your building. 

Ready for peace of mind this winter? Talk to our roofing experts here.