What Are Ice Dams on Commercial Roofs? And Why You Should Care

If you’ve ever noticed thick ridges of ice forming at the edge of your commercial roof after a heavy snow, you’re likely dealing with ice dams. They might not seem like a big deal at first—just frozen water, right? But the truth is, ice dams are a warning sign of serious problems that can lead to expensive roof damage, interior leaks, and even structural issues. 

At Weather Shield Roofing Systems™, we’ve been helping commercial property owners and facility managers protect their investments for over 40 years. Ice dams are one of the most common winter roofing issues we see in cold climates—and one of the most misunderstood. 

Let’s break down what ice dams are, what causes them, and why they matter so much for the long-term health of your commercial roofing system. 

What exactly is an ice dam? 

An ice dam is a buildup of ice that forms at the edge of a roof—usually near the eaves—preventing melting snow from properly draining off the roof. As more snow melts (usually due to heat escaping from the building), the water gets trapped behind the ice and has nowhere to go. Eventually, that water backs up and can seep under the roofing membrane, flashing, and insulation. 

On commercial flat roofs, ice dams don’t always look like long icicles like they do on residential sloped roofs. Instead, they often collect near drains, scuppers, or parapet walls, where water is supposed to escape. When that drainage gets blocked by ice, pooling water can lead to leaks and damage fast. 

Why do ice dams form on commercial roofs? 

There are a few key factors that cause ice dams on commercial roofs: 

• Poor insulation or heat loss: When heat escapes from inside the building and warms the roof unevenly, snow melts and refreezes near cold spots like eaves or drain areas. 

• Inadequate roof drainage: Flat or low-slope roofs rely on internal drains, scuppers, and downspouts to clear water. If these are clogged or frozen, water gets trapped. 

• Sudden temperature swings: Freeze-thaw cycles are notorious for turning melting snow into layers of ice that build up quickly. 

• Improper roof slope or ponding issues: Even a “flat” roof needs slight slope to direct water. Standing water from past storms can freeze and create more ice dams. 

If your roof isn’t draining properly, or if heat is escaping where it shouldn’t, you’re at a higher risk of developing ice dams—especially in older buildings or facilities with aging insulation. 

Why should commercial property managers care about ice dams? 

It’s easy to ignore a little ice, especially when you’re focused on running a business or managing multiple properties. But ice dams can create serious headaches if they’re not addressed early. Here’s why: 

Can ice dams cause roof leaks?

Absolutely. Once water backs up behind an ice dam, it often finds its way into seams, under the membrane, or through roof penetrations. That trapped moisture can leak into ceilings, walls, and even electrical systems—causing thousands of dollars in interior damage. 

We’ve seen businesses shut down sections of their building due to leaks caused by unnoticed ice dams. It’s not just a roofing issue—it’s a business interruption risk. 

Can ice dams damage the roof itself?

Yes. Ice is heavy, and when it’s allowed to build up unchecked, it can damage roofing materials, pull at flashing, and weaken the integrity of the roofing system. Flat roofs can even suffer structural stress if water pools and freezes repeatedly in the same areas. 

Over time, the freeze-thaw cycle can shorten the lifespan of your commercial roof, even if it’s relatively new. 

How can I tell if my commercial roof has an ice dam? 

Here are some warning signs: 

• Ice forming near drains or edges after snowfall 

• Large icicles hanging from gutters or scuppers 

• Water stains on ceilings or walls inside the building 

• Unusual pooling or frozen water areas on the roof deck 

• Gutters or downspouts that aren’t draining properly 

If you notice any of these signs, it’s a good idea to schedule a commercial roof inspection right away—especially if you’ve had problems with ice or snow in the past. 

What should I do if I already have ice dams? 

The most important thing is not to try and break the ice yourself. That can damage the roof membrane or cause injuries. Instead: 

• Call a commercial roofing professional who has experience with winter roof maintenance. 

• They may recommend safe steaming or ice melt treatments that won’t harm the roof system. 

• It’s also important to check for hidden water damage beneath the ice to catch leaks early. 

At Weather Shield Roofing Systems™, we offer emergency winter roof repair services and proactive roof maintenance plans like Max Life™ Roof Care to help you stay ahead of seasonal risks. 

Ice dams might seem like a winter nuisance, but they’re often the first sign of deeper roofing issues—like poor insulation, drainage problems, or membrane failure. The good news? With the right care, they’re totally preventable. 

At Weather Shield Roofing Systems™, we’re here to help you prevent damage, avoid costly emergency repairs, and keep your commercial roof performing through every season. If you’re seeing signs of ice dams or just want to make sure your roof is winter-ready, contact us today. We’re always ready to help you protect your roofing investment with honest, expert advice and proactive solutions.