Commercial Property Insights

Preventing Snow load–induced Structural Failures

Adverse weather conditions can threaten the structural integrity of a building. In particular, snowfall can lead to snow load–induced structural failures, including partial or complete collapse. This article discusses the potential damage snow can do to commercial properties and what you can do before, during and after a major snow event to prevent structural failures.

Potential Damage

Heavy snow, high winds and frigid temperatures can create the perfect conditions to cause structural damage. Snowfall can cause extensive damage to commercial properties, such as:

  • Roof collapse—Snowfall can cause a roof to collapse by putting pressure on it, and even a moderate amount of snowfall could lead to a snowdrift that causes structural damage. Additionally, improper drainage can cause snow, ice and water to remain trapped on the roof, adding weight that can put a roof at risk of collapse.
  • Ice dams—An ice dam forms when snow melts on an upper, warmer part of a building’s roof, then flows down to a colder part and refreezes, creating a blockage that prevents additional snowmelt from draining. The excess water can leak into the building, damaging walls, ceilings, insulation and other areas.
  • Frozen pipes—Frozen water exerts thousands of pounds of pressure per square inch, and extensive water damage can occur when frozen pipes burst.

Understanding the damage a building can incur as the result of winter weather can help commercial property owners prepare before an impending storm strikes.

What To Do Before a Major Snow Event

Preparation for snowfall should begin at least six to 10 weeks before winter so there is ample time to fix any problems that arise. Before a major snow event, commercial property owners should:

  • Ensure the building structure and roof are in good shape. Check the framework for any damage or weakness, and reassess the roof’s snow-load capacity. Repair any structural deficiencies.
  • Develop a response plan. Assign tasks and roles to help reduce confusion during a snow event, including whether snow removal will be done by inhouse crews or contractors. This plan will also help ensure that nothing is overlooked.
  • Prepare an OSHA-compliant safety plan. Make sure workers are safe during snow removal work and inspections by formulating a safety plan that includes roof access and edge fall protection requirements.
  • Examine removal equipment. Ensure all shovels, snowblowers and other equipment are in good condition before the start of winter. In addition, never use any equipment that can damage a roof, such as an ice chopper.
  • Inspect all drains for debris. Remove all leaves, dirt and silt from drains and downspouts to prevent snow buildup.
  • Secure snow removal contractors. Many organizations rely on contactors for removing snow from structures. It is important to ensure that agreements with contractors are signed before winter and snow removal plans are reviewed.

What To Do During a Major Snow Event

A large snow load on a commercial building’s roof can cause problems as soon as it’s allowed to buildup. During a major snow event, review the response plan for details on snow removal. The plan should include details for determining the approximate snow load at which snow removal should begin. In regards to snow removal:

  • Follow all OSHA rooftop safety protocols
  • Use roof fall arrest harnesses where applicable
  • Steer foot traffic away from locations where falling snow or ice could result in injuries
  • Remove snow from the roof in increments
  • Do not allow unauthorized workers or people on the roof
  • Do not create snow drifts by taking snow from one area of the roof and putting it on another
  • Check to see that drains are clear of ice and snow

What To Do After a Major Snow Event

After receiving the “all-clear” signal from local agencies and emergency personnel, post-winter storm measures can begin. Once the snowfall has subsided:

  • Remove the remaining snow. Even if the snow accumulation following a major snow event doesn’t surpass the building’s safety threshold, snow removal may still be necessary.
  • Examine the interior and exterior of the property. Inspecting the interior and exterior building can allow commercial property owners to assess and document any damage that may have occurred during the snowfall.
  • Look for tree damage. If a tree has heavy snow accumulation on its branches, it could fall and damage the exterior of the commercial property. A professional can trim them properly.

Conclusion

Since snow accumulation is a common occurrence in many parts of the country, it’s important for commercial property owners to take the proper steps before, during and after a major snow event to prevent and repair any damage. For more information, contact us today.

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