All You Need To Know About Ice Damming
What Is An Ice Dam?An ice dam is an ice ridge formed at the edge of a sloping roof. It serves as a blockage that stops melting snow from falling of the roof. Ice damming usually occurs after a snowstorm and it causes the water (from melting snow) that accumulates behind it to leak into the house. This can eventually damage the insulation, ceiling, walls and other parts of the building.
Why Ice Damming Occurs
Ice dams usually occur after snow falls for several days with freezing temperatures. Uneven roof surface temperatures lead to ice damming. This non-uniform temperature is caused by the interaction between the heat escaping from the house, the amount of snow cover, and the external temperature on the roof. Ice dams usually form when the average temperature of the lower portion (near the edge) of the roof is below 32 degrees Fahrenheit while the temperature of the upper section is above 32 degrees Fahrenheit.
When snow falls on the hotter portion of the roof, it will melt and start flowing down the roof till it gets to the colder portion with a temperature below 32 degrees Fahrenheit, then it freezes to form an ice dam. As more melting snow gets to the ice dam, it will grow bigger. Consequently, the water from the melting ice will begin to gather behind the ice dam. This water will eventually locate cracks or openings in the roof shingles or covering and flow into the roof deck and attic space.
The heat source for the section of the roof with higher temperature is usually within the house. Heat could be transferred from the house through the ceiling to the attic space due to air leakage. Also, exhaust systems that are used in the kitchen and bathroom which terminate just above the roof can contribute to snow melting. In addition, using fireplaces or wood stoves permits heat to be transferred into the attic space from the chimney. Attic spaces with poor insulation and leaky ducts could serve as a source of heat for various sections of the roof.
The Dangers Caused by Ice Dams
Ice dams are dangerous because they make water leak through the roof into the ceiling and walls of the building. This could lead to roof rot in the decking, framing and sheathing. Water that infiltrates into the wall cavities may cause the paint to peel off. The insulation in the attic will also become soggy and ineffective. Due to the growth of mildew and mold, serious respiratory diseases like asthma and allergies could occur. In addition, ice dam and icicles that form at the roof edge may become rather large (sometimes they weigh hundreds of pounds) and break off all of a sudden. Consequently, the roof gutter, siding and shingles at the edge may be seriously damaged and even fall off and injure people who are standing beneath the roof.
What To Do When Your Roof Has Ice Damming?
When an ice dam occurs on your roof, you may be tempted to remove the ice dam and icicles by chipping them away. This could be extremely dangerous. You could damage your roof shingles, and get injured by ice and debris that falls off your roof. Instead, you should contact a roofing contractor or professional roofer immediately. A roofing professional has the knowledge, tools and experience to help you take care of the entire situation. This is best and safest way to get rid of the ice dam.
How to Prevent Ice Dams
Getting rid of an ice dam will help you to avoid all the dangers associated with it but you need to take steps to prevent repeated formation of ice dams on your roof. Start by sealing off all the air leaks in your attic. This will eliminate warm air leakage that heats up the upper portion of your roof. After you have sealed off the leaks, put additional insulation in your attic. Sufficient attic ventilation is key to minimize the build up of hot air and ensure that the interior and exterior roof surfaces are at the same temperature. Before the winter season sets in, always clear out leaves and other kinds of debris from the roof gutters.