Roof Collapse due to Snow Loads: Common Causes and Prevention Strategies

Mark A. Churpek, Associate Principal
David A. Schnerch, Associate Principal

Each winter, the accumulation of ice and snow results in a number of partial or complete collapses of commercial, low-slope roof structures. These failures typically occur because of a combination of circumstances—seldom solely from a “once-in-a-lifetime” snowfall on an otherwise well-maintained and appropriately designed and constructed roof structure.

Building owners and managers should understand and take into consideration a number of factors when evaluating the pros and cons of potentially removing snow from a roof to reduce the risk of collapse of their buildings. This starts with an accurate assessment of the weight of snow and ice on the roof and includes an appreciation for the difference between design and ultimate capacities as well as an understanding anticipated structural behavior of a heavily loaded roof structure. 

In this webinar, David Schnerch, P.E., and Mark Churpek, P.E., discuss conditions that often contribute to structural roof failures due to ice and snow, various options for monitoring accumulation, and suggested practices to remove ice and snow, if warranted. Relevant case studies will be used to illustrate potential pitfalls.

By the end of the presentation, you will be able to:

  • Identify common causes of winter weather-induced roof collapses
  • Describe what tasks might be beneficial to perform before the winter season to reduce the risk of collapse from ice and snow accumulation
  • Determine how to accurately measure roof ice and snow loads and compare measured loads to design loads to make an informed decision on whether ice and snow removal is warranted
  • Develop a rational and efficient ice and snow removal plan that will minimize the potential for roofing damage