This winter has already brought record cold temperatures to many parts of the country. Along with the frigid weather, snow and ice have blanked many regions. It is during these freezing temperatures that a ridge of ice may form on the edge of a roof. This is known as an ice dam and it can allow water to back up behind it and leak into a home or building resulting in water damage and potential mold growth.
According to the U.S. Government’s Energy Star Program website, “Ice dams usually occur after a heavy snowfall and several days of freezing temperatures. Warm air inside your home leaks into the attic and will warm the underside of the roof causing snow and ice on the roof to melt. The melted water will drain along the roof, under the snow, until it reaches the cold overhang. The overhang tends to be at the same temperature as the outdoors and the melted water will refreeze and form an ice dam and icicles. The ice dam can cause damage to the roof, which will result in water leaks to the inside. Frequently the result will be a water spot on the ceiling under the roof damage.”
Fortunately, ice dams can be prevented by controlling heat loss from the building into the attic. Keep warm and moist air from entering the attic space from the interior of the building by sealing any air leakage pathways and be sure the attic is properly insulated. Vented appliances should be exhausted to outside of the building and not into the attic. Proper attic ventilation can also help to keep a uniform roof temperature.
“If an ice dam causes water to leak into a building, it can cause staining, water damage and allow for the growth of mold,” said Jason Dobranic, Ph.D., Vice President of Microbiology and Life Sciences at EMSL Analytical, Inc. “Even mold growing above ceilings and in wall cavities can impact the indoor air quality of a building. Exposure to elevated levels of mold can cause respiratory issues such as allergies and hypersensitivity pneumonitis, trigger asthma in people with the condition, and some types of mold can even cause infections in people with a weakened immune system.