Dealing With Heavy Snow Buildup On Flat Roofs

Commonplace on commercial properties, flat roofs are now also a growing trend on many modern homes. Whether you own a commercial building with dozens of occupants or a modest home with just your family, knowing how to deal with excessive snow buildup is important for your roof's long-term health.

How Heavy Snowfall Affects Flat Roofs

Without a steep slope to help shed some of the excess snow buildup, flat roofs are particularly prone to accumulating heavy snowfall. Flat roofs are especially prone to the following problems:

Excessive loads. Excessive snow accumulation can affect just about any type of roof, but flat roofs are more prone to accumulating loads that place extreme pressure on the roofing structure. These extreme loads can cause bowing, create low spots ideal for ponding water, and allow certain areas of the roof to deteriorate and become primed for an eventual collapse.

Ponding water. Whereas sloped roofs can develop ice dams due to excessive snow buildup, such buildup can also leave behind ponds of snowmelt. Ponding water can seep through roof membranes, resulting in water damage within the roofing structure and annoying leaks within buildings.

Freeze/thaw cycles. Ponding water is also subject to freeze/thaw cycles. Frozen snowmelt expands as it freezes, allowing cracks and gaps to widen and become more prone to leaks when it thaws.

If you own a commercial or residential building with a flat roof, you can't afford to ignore heavy snowfall. Doing so could put both your property and those inside at incredible risk of injury or worse. The sheer weight of excessive snow buildup can cause the roof structure to buckle and collapse without warning.

Tips for Safe Snow Removal

Removing heavy snow buildup from a flat roof requires a slightly different approach compared to traditional sloped roofs. Here are a few helpful tips you can use to remove snow buildup without damaging your flat roof:

  • Identify and mark off vents, pipes, and HVAC equipment prior to snow removal. Doing so will help prevent expensive damage and time-consuming repairs.
  • Clear a path for discarded snowfall. Create a protective cordon around the building to protect occupants and other pedestrian traffic.
  • Use the right equipment for rooftop snow removal. Plastic and soft aluminum roof rakes and shovels are preferable to hardened steel that can leave behind gouges and scrapes in the roofing membrane.
  • Carefully clear away all but approximately one inch of snowfall above the roof's surface. You'll leave behind a little snowfall, but it's better to let it melt away during warmer weather than risk damaging the soft roofing membrane underneath.
  • Only use de-icing products that are compatible with your roofing membrane. Using the wrong de-icing material could damage your roof; if you plan to use de-icing cables or mats, make sure they're rated for safe use on your flat roof.

Tips for Preventing Excessive Snow Buildup

Prevention is also an important part of protecting your flat roof from heavy snow buildup. Here are a few preventive steps you can take to keep your roof in good shape while protecting your building's occupants:

  1. Clear your roof regularly to prevent excess snow from building up. If you're not comfortable with clearing your own roof, you can hire a professional to do it.
  2. Have your roof inspected by a professional on an annual basis, preferably before fall weather arrives.
  3. Invest in a good waterproofed membrane that offers a watertight seal against snowmelt.
  4. Keep gutters and drain spouts free of any debris that could block proper drainage of snowmelt.
  5. Check your roof for proper insulation, as a poorly insulated roof can allow building heat to penetrate attic and crawl space areas and create the conditions for ice dams and ponding water.

For more information, get in touch with a company that offers flat roofing services.

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