Winter Weather Effects on a Commercial Roof
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Winter is nearly here and the National Oceanic and Atmospheric Administration has released their predictions for the coming season.
“This winter, NOAA predicts wetter-than-average conditions for the entire northern tier of the continental U.S., particularly in the Pacific Northwest and the Great Lakes region, along with northern and western Alaska. Meanwhile, drier-than-average conditions are expected from the Four Corners region of the Southwest to the Southeast, Gulf Coast and lower mid-Atlantic states.” Source NOAA
Winter weather can wreak havoc on commercial roofs in several ways, with the biggest being the inevitable freeze/thaw cycle.
Freeze-Thaw Cycle Effects on a Roof
As water seeps into the roof membrane, it will expand when frozen. This can cause penetrations, cracks, or openings to spread or enlarge. The repeated freeze/thaw cycle that happens in the winter months can significantly deteriorate the roof membrane, causing it to become brittle and susceptible to leaks.
Flashing is a material installed on a roof to waterproof critical areas like around HVAC units, walls, exposed gaps, joints, and more. Flashing is vulnerable to high winds and ice formations. It can become loose or fly off altogether in extreme wind zones. As ice forms around these at-risk locations on the roof, it can cause cracking and as it melts, allow water into the roof system.
Other Winter Weather Hazards on a Roof
Condensation: If your facility has inadequate insulation and/or poor ventilation, you may experience condensation issues. Basically, warm air escapes the building and hits the cold roof (or walls), causing condensation within your facility. If condensation isn’t addressed quickly, it can lead to mold, mildew, interior damage, and more.
Wind: High winds can result in damaged flashings, open seams, and torn laps.
Snow: For flat or low-slope roofs, snow can accumulate and create immense pressure on the rooftop. All roofs have a maximum weight limit so it’s important to understand how much your roof can hold and how heavy snow and drifts can be. Fresh snow, packed or old snow, and ice vary greatly in terms of pressure and weight. Snow should be professionally removed from the roof whenever possible to avoid build-up and possible roof collapse. Never try to remove snow yourself. It’s extremely dangerous and can cause even more damage to your roof.
