Carrying the Weight: Removing Rooftop Snow Loads

If your commercial property is in a region that gets a lot of snow in winter, you might have dealt with the problems stemming from snow piling up on your roof before. A heavy snow load can harm the commercial roof, property, inhabitants, and investments below. Snow can cause structural damage and create safety risks, which may lead to liability issues for the property owner.

What is a Rooftop Snow Load?

Snow load refers to the weight of packed snow on your commercial. Engineers consider a roof’s structural load when they design and construct a building. The structural load has two parts: the dead load, which is the permanent weight of the structure itself, and the live (temporary) load, which, in this case, is the weight of snow on the commercial roof. FEMA’s Snow Load Safety Guide states that several factors affect snow load. These include the property’s size, wind exposure, roof obstructions, and geographical location.

The pressure from snow and ice on your commercial roof can change based on the moisture content of the snow. Factors like your roof’s structure, snow accumulation, and distribution affect how well your commercial roof can handle the additional snow load.

How Heavy is a Snow Load?

A cubic foot of snow can weigh anywhere from 7 to 30 pounds. Because snow weight varies, figuring out how much snow is on your roof is not as simple as just adding the weight for a certain depth. On top of that, (as mentioned) snow is significantly heavier after it gets rained on.

Depending on the wind’s direction, drifting can cause snow to pile up on one side of the commercial roof’s features. These areas are more at high risk and need closer monitoring. When it comes time to remove snow, roofing experts start with these vulnerable spots.

Can my Commercial Roof Handle the Additional Weight?

Here is a list of warning signs that commercial properties may exhibit if overburdened by the weight of snow:

• Ceiling issues can expose themselves as sagging sections or lower-than-usual sprinkler lines and heads.
• Strange sounds like creaking, popping, or cracking often indicate a roof under stress.
• If any part of the roof or truss appears to sag, it should raise alarms.
• Ponding water on a flat roof suggests that a specific section may have sunk, which might only be evident after the snow melts.
• Doors or windows that stick or won’t open could mean the roof or walls have shifted due to snow weight.
• Cracks in drywall, masonry, and other wall materials can occur when an overloaded roof puts too much pressure on them.

What Can I Do to Help?

Building codes addressing snow loads were not updated until the 1970s and 1980s. If your building is over 50 years old and has additional equipment added to the roof, it might be vulnerable to roof collapse during heavy snowfalls.

A regular maintenance program is essential to keep your commercial roof in good shape. Have your roof inspected at least twice annually to ensure the drainage system is clear of debris and functioning optimally. Don’t forget to check gutters and downspouts as well. The best times to schedule roof inspections are in spring and fall. This prepares your roof for any harsh weather that may come.

You can take several steps to lower the risk that snow presents to your roof and to minimize snow drifts on a flat roof:

• Schedule a professional roof inspection before the snow season starts. Focus on areas more likely to be affected by snow and ice. Fix any problems found before the snow comes.
• Consider installing wind baffles to prevent snow from entering drainage systems, vents, and other openings.
• Snow guards are useful, especially on metal roofs, but can also benefit flat roofs. They help keep plumbing vents and airways clear of snow.
• Creating a roof map can make snow removal easier. Mark locations of roof features, the drainage system, and areas where snow tends to build up. A commercial roofing expert can help create this map for you.

PB Roofing’s Rooftop Snow Removal Services

Heavy snowfall and freeze-thaw cycles can quickly create dangerous conditions, and a roof collapse causes significant damage to your building and the people inside. Snow and ice can damage gas lines, water piping, electrical conduits, and other rooftop accessories. Snowfall accumulation can lead to roof leaks, icicle formations, and structural concerns.

Our trained PB team is ready to be deployed and can help you keep everything safe—before, during, and after the storm.

Expand Your Knowledge with Relevant Blog Back Issues

A 4-Step Guide to Preparing Your Commercial Roof for Winter (October 2024)

Commercial Roofing Uncovered: Did Your Roof Survive Winter? (February 2024)

Connecting the Top 4 Ways to Understand, Identify, Prevent and Fix Freeze-Thaw Damage (September 2023)

Think it’s Too Early to Worry about Snow? Think Again. (September 2022)