Ice dams are only a problem in winter, but summer is a great time to educate your customers and the public about risks and prevention. No one wants to climb into an attic or work outside when the weather is frigid. But now it’s warm enough to do something about the insulation and ventilation issues that contribute to the problem.
What is an Ice Dam?
A string of icicles dangling from the roof might be pretty, but they’re more than a simple side-effect of frigid winter weather. An accumulation of ice along a roof’s edge is usually considered an ice dam.
When snow collects on the roof and the underlying layer melts, water runs to the edge of the shingles. Then when the temperature dips, often overnight, the melting water freezes again and forms a ridge or dam. This dam prevents holds melting water back and prevents it from draining off into the gutters.
Why Are Ice Dams Such a Big Deal?
A fee icicles probably won’t cause any harm. It’s a widespread ice dam issue that goes unchecked that causes so many headaches. When ice forms and water backs up, it has nowhere to go. One of the first signs that homeowners usually see is a water leak inside the home, usually along the ceiling line of an exterior wall.
Chronic freezing along the roof’s edge can also lift shingles. In time, it can break them. Because ice is heavy, it can loosen gutters or pull them off the house entirely. If the problem happens every winter, chances are, insulation in the attic has been soaked more than once and long since been rendered ineffective.
How Do Ice Dams Form?
The temperature of the roof and the temperature outdoors contribute to the formation of ice dams. Generally, the surface temperature of the roof’s edge must be colder than the rest of the roof. The University of Minnesota says, “There must be snow on the roof, and, at the same time, higher portions of the roof’s outside surface must be above 32 degrees while the lower surfaces are below 32 degrees.”
This temperature difference often happens when the home’s ventilation and insulation are inadequate for the job. If the home loses too much heat, enough to warm the roof, snow cover will begin to melt. And if there’s inferior ventilation to keep the roof uniformly cold, melting water will re-freeze once it reaches the colder roof overhang.
How Can Homeowners Prevent Ice Dams?
There’s no shortage of gadgets that claim to prevent ice dams, but there’s really only one cure. Heat tapes, for example, only work in certain conditions and they often don’t work if the weather is very cold. If a homeowner uses heat tape for extended periods of time, it can cause the shingles to break down.
The best solution is better attic and eaves insulation and ventilation. Beefing up the attic insulation helps hold more heat down in the living areas of the house. Blocking off air leaks, such as gaps around plumbing and electrical penetrations, helps, as well. Better ventilation in the attic and along the eaves helps heat that enters the attic dissipate before it can warm the roof.
Ice dams are a common problem in areas where snow accumulation is a normal part of winter weather. But just because they’re common doesn’t mean they’re benign. Talk with your home inspection customer about the risks of ice dams and how to prevent them. Now that winter is over, it’s the perfect time to update insulation, ventilation and any shingles and gutters that have taken a beating.
If you’d like to help people in your community make educated decisions about homeownership, becoming a certified home inspector is a great career path. ICA School can help with our comprehensive education program and a vast library of additional resources. Enroll now and start learning the trade at your own pace.