Winter Steel Building Maintenance: Preventing and Addressing Ice and Snow Build-Up

The worst of winter is upon us, and the heavy snow that some areas have or will undoubtedly experience this season can cause serious problems for steel buildings when not addressed.

Snowy scenes and landscapes are often picturesque, but the quick build-up of additional weight on a structure’s roof can pose new dangers to that building’s occupants or users. To help avoid injury or damage, let’s re-visit some of the basic concepts of buildings loads, how heavy snowfall and ice accumulation impact these, and finally how we can address snow and ice build-up before they cause any damage.

A Quick Refresher on Building Loads

We published an overview of building codes and loads a little over a year ago – you can read that blog article by clicking here. While we won’t go into that much detail again, let’s quickly re-examine the basics of what building loads are, and why they exist as minimum standards for your structure to adhere to.

While a building should have many desirable characteristics, including an attractive appearance, long life, flexibility of use and economy, at the most fundamental level it must offer protection for the people or property inside of it. The term building loads is used to refer to any weight or force that is exerted upon a building, including snow, ice, rain, and even the building materials themselves. Building codes, on the other hand, are how jurisdictions regulate building construction through the codification of minimum load standards.

There are two primary types of building loads we need to consider when discussing the effects of winter weather on a structure:

Dead Loads

Dead loads refer to the total weight and resting loads of the building itself. This includes all of the building materials, including the roof, framing, insulation, and panelling.

Live Loads

Live loads are variable loads that fluctuate throughout the life cycle of the building. These can include things like the weight of workers and their equipment while they are constructing or performing maintenance on the building but can also include things like changing wind and snow forces. In Canada, the minimum standard for live loads is 21 pounds per square foot.

Effects of Snow and Ice on Structural Integrity

The wide variety of climates across North America means that different areas will experience different amounts and consistencies of snowfall throughout the year. These two factors – amount and consistency – are what determine safe vs dangerous amounts of snow accumulation.

A single square foot of light, powdery snow can weigh less than a pound – nothing to be concerned about as far as structural integrity goes. However, the wetter and more packed snow becomes the denser and heavier it becomes. When wet, that same square foot of snow can weigh up to ten times as much as the same powdery snow. And, as snow melts and then re-freezes into ice, it weighs about 5 pounds per square foot! In essence, the more water content in the snow, the heavier it will be, with ice being the heaviest form of build-up your roof is likely to experience.

The other thing to keep in mind when examining the roof of your steel building, is that snow and ice don’t typically settle in a uniform way. Windy conditions, roof angles, as well as features like chimneys, gutters, and vents, can all affect where snow and ice accumulate on your building’s roof. So, even if your area doesn’t experience vast amounts of snowfall, if that snow is accumulating in particular areas of your roof and freezing into ice, this could exceed your building’s weight capacity. It is absolutely crucial you remain aware of where snow and ice are building up on your roof, and to what extent it is forming into ice. 

The Danger of Ice Dams

On the topic of ice accumulation, one of the worst scenarios that can develop on your roof is the formation of an ice dam. When a roof is improperly or inadequately insulated, portions of the roof become warmer than the surrounding air. When this happens, snow melts on the warmer portions of the roof and flows down the slope before pooling and re-freezing on colder areas of the roof. When this process happens continuously over a period of time, this build-up forms what is called an ice dam.

Ice dams are so potentially destructive because of their weight – as they form what are essentially thick barriers of ice – but also because they dam any further water that builds up. As they form blockages on your roof, water will pool behind the ice rather than run down and off the roof. This built-up water can force its way through small gaps or imperfections in your roof. This is the true danger of ice dams – once water begins making its way through small gaps or spaces in your roof, the water damage to your structure or property can be severe.

The best way to prevent the formation of ice dams, as strange as it may sound, is to keep your roof cold. The better your building and roof’s insulation is, the more consistent the temperature will be across the entire surface area. If the entirety of your roof remains cold, then ice and snow will melt in a uniform matter and won’t have an opportunity to re-freeze while still on your roof. To learn more about the different types of insulation that are available for your steel building, click here to read our short article on steel building insulation.

Preventing and Addressing

There are two ways to tackle snow and ice accumulation: through preventative design and maintenance before the snowfall, and through active clearing of excess snow and ice after the snowfall as occurred.

All of Norsteel’s buildings are designed with heavy snowfall in mind, and every building we offer either meets or exceeds the standards set by the Canadian government. If your building needs to be in an area with extreme amounts of snow, we’ll work with you to ensure your building is strong enough to handle whatever the local conditions are. In addition, our standard roof design uses a 2/12 pitch which should allow for most of the ice and snow to simply roll right off your roof. This slope is usually enough to clear most of the snow build-up from your roof.

While all of our buildings are designed to handle tough weather conditions, sometimes storms can throw more at them than what can be reasonably anticipated. In these special circumstances, you may need to take a more active role in clearing some of the snow and ice from your roof. The best way to do this is through the gradual removal of excess snow. Roof rakes are excellent tools to use in these situations – from the safety of the ground, you can clear built-up snow without having to stand on a ladder or the roof itself. We strongly discourage physically getting on top of the roof. This is best left to professionals given the slippery conditions, and footprints – if not cleared properly – can pack down snow and lead to the formation of ice dams.

Stay Safe This Winter

If you partnered with Norsteel to construct your steel building, then you can rest easy knowing that your structure is designed to meet the local weather conditions of your area. However, preventative maintenance is always a recommendation, and extreme weather conditions can always arise and cause unforeseen damage to your building.

If you have any questions or concerns about the impact of snow and ice build-up on your steel building, feel free to reach out to us by clicking here. Our expert building consultants are standing by to help you with anything you may need.