Can Snow Damage My Building’s Roof?

If you own property in Delaware, you know winter weather here sometimes brings heavy snow. That might require more maintenance than other times of the year.

On a low-sloped or flat roof, snow can cause damage if there are large accumulations. Heavy snow can create a load too heavy for the roof, resulting in structural damage. Along with snow damage, ice dams can also threaten the integrity of your building’s roof.

The good news is that a damaged commercial roof doesn’t necessarily mean you’ll need an entire roof replacement.  Mid-State Roofing repair your commercial or industrial roof with a Conklin roof system to fix leaks caused by snow damage. If repairs prove to be extensive, we offer commercial roof installation as well.

How Much Snow Is Dangerous for a Roof?

While the depth of the snow and the amount of snowfall on your commercial building matters, it isn’t the only way to determine the threshold for roof danger.

Snow weight can vary depending on how much moisture is in the snow. Remember when you were a kid and sometimes the snow was perfect for building a fort while other times the snow wouldn’t stick to itself?

Snow water equivalent (SWE), or the more water in the snow, impacts the weight of the load your building must withstand. Accumulation of snow, rainfall that follows, and ice all add to the load.

Fortunately, commercial buildings are typically designed with ample snow-load values. Large, post-frame buildings often used for agricultural purposes, however, do not always have snow load in mind when they are designed.

How Do I Calculate Snow Load?

Gather snow in a bucket 1 foot high. Weigh it (minus the weight of the bucket when empty). Next, find an area on your roof that represents the average depth of the snowfall. (That is, don’t measure a pile of snow that is drifted up against a parapet because the depth there will not be a good representation of the norm.)  Measure the depth at that spot in feet.

Take the depth of the snow in feet times the weight of the cubic foot of snow to determine the pounds of pressure per square foot. Multiply that by the number of square feet on your roof to determine the snow load. For ease, see the chart below for estimated snow loads.

Depth of Snow (ft.) Dry Snow (pounds per square ft.) Wet Snow (pounds per square ft.)
1 3 21
2 6.5 42
3 9.5 62
5 15.5 104

Source: Curt A. Gooch, Cornell University

How Can I Prevent Snow Damage?

You can protect your flat roof from snow damage by having it inspected annually. Delaware’s Mid-State Roofing offers free commercial roof inspections. We can spot drainage issues and weak spots in your commercial roof system.

Know your roof’s weight limits and continuously check for any signs of damage during and after a snowfall. Look for sagging, bowing, leaks, and cracks. Consult a professional roofer if there are signs of damage.

One of the best ways to protect your commercial roof is to apply a roof coating. We specialize in the installation of Conklin roofing systems and commercial roof coatings through high-quality Conklin products. Call us today to learn more.