Parts of the country have experienced record snowfall this year, and winter is far from over. While snow and ice removal may bring to mind shoveling walkways and scraping ice off windshields, removing snow and ice accumulations from rooftops and awnings is an equally important practice. That’s why we’re presenting these timely snow and ice removal tips.
Water damage is often the focus of risk prevention for roofs, but excessive snow and ice buildup can also introduce the risk of collapse. Winter precipitation can be visually deceptive, making it hard to judge just how much weight your roof is holding at any given time. If you haven’t done so lately, we recommend taking some time to refresh your maintenance staff on the snow load capacity of any facility your tribe or tribal enterprise may own, and to continually assess and address snow and ice accumulations. Stay on top of snow and ice removal this winter with the following steps.
Related: Preventing ice dams at your business property
Step 1: Know your roof.
Each facility is different, and a “one size fits all” approach may not be suitable for roofs of varying designs. Consider the following questions when assessing a roof for the potential risk of collapse or water damage due to snow and ice accumulation:
Slope. Is your roof steep? Is it a gradual slope? Is it flat? These will be important factors in determining how much snow is likely to accumulate at any given time, how quickly it may melt, and what kind of drainage or refreezes you can expect to see accumulating at awnings.
Continuity. Does your skyline follow a symmetrical pattern, or is it varied? Are there covered porches or walkways? Are some portions of your building taller than others? Snow and ice tend to accumulate more rapidly on overhangs and in places where lower sections of the roof meet up against taller portions of the building. Knowing in advance which areas of the roof are more susceptible to buildup and potential drifting is important knowledge for your maintenance personnel.
Integrity. How old is your roof? What is its maintenance history? How much weight is it rated to bear? According to the Insurance Institute for Business & Home Safety (IBHS), the roof of an average residential building can carry up to 20 lbs. per square foot before coming under stress. However, it is very likely this number may vary across other kinds of commercial facilities. If the weight rating of your roof is not known, we recommend hiring an appraiser to assist your maintenance staff in determining how much snow and ice it can safely bear.
Related: Prevent winter water damage
Step 2: Accurately interpret snow and ice loads.
While rain, snow, and ice are all made of the same basic element, they are all very different in terms of volume and weight. These two properties can be especially tricky to judge for snow, as it comes in a multitude of its own unique forms: fresh, powdery, wet, hard-pack and so on. The following information can help you stay on top of snow and ice removal this winter by illustrating how volume and weight are not always relative:
5 lbs. per square foot is equal to (approximately):
- One inch of standing water
- Ten to twelve inches of fresh snow
- Three to five inches of packed snow
- One inch of ice
Related: Essential winter weather preparation
Step 3: Continuously monitor roof accumulations.
Winter precipitation is often a cumulative process. Consider the following scenario of a flat, residential roof with an inadequately maintained drainage system:
- A winter storm deposits a foot of fresh snow.
- A week of temperature fluctuations causes some of the snow to melt and then refreeze in a two-inch layer of ice.
- As time passes, the remaining snow gradually compresses into packed snow.
- Overnight freezing rain seeps into the packed snow, adding an additional inch of water weight to the snowpack.
- A second winter storm deposits an additional foot of fresh snow upon the roof, which also compresses over time.
This fictional roof is now dangerously close to bearing upwards of 20 lbs. per square foot. Depending on how well the roof has been maintained, or whether it sustained water damage in previous winters, parts of the roof may have become susceptible to collapse long before reaching the 20 lb. per square foot average.
Regardless the scenario, the important thing to remember is that a roof’s snow load is a constantly evolving scenario, and the weight of snow and ice can be visually deceiving.
Related: How to protect outdoor workers from cold stress this winter
Step 4: Stay on top of snow and ice removal this winter
It’s important to have mitigation strategies in place should your roof start to become overburdened. If your tribe or tribal enterprises own facilities in regions where heavy snowfall is a regular occurrence, investing in a roofing heat cable system might be a solution worth exploring.
In lieu of that, regularly removing snow and ice with roof snow scrapers may be something to consider adding to regular maintenance workflows. Alternatively, contracting with a company that specializes in snow removal may also be something to consider.
Don’t let the roof cave in – come rain, sleet, or shine, make sure you stay on top of snow and ice removal this winter. If you have questions, please reach out to your broker or tribal risk manager, Mark Sherwood, at email@example.com.
Information for this article has been adapted from an article by the Insurance Institute for Business & Home Safety (IBHS).