Dam! You might have Ice Dams!
During the winter, most homeowners wouldn’t expect water damage to their home. After all, how can water leak into your home when it’s so cold outside, shouldn’t it stay as snow or be frozen? As it turns out, there is a way for water to sneak into your home, even when everything should be frozen. The reason? An interesting phenomena known as ice dams.
What are ice dams?
Ice dams are a buildup of ice along the edges of a roof caused by melting snow turning into water. These buildups will slowly grow over time. Eventually, the ice will grow tall enough to create a dam, blocking future snowmelt from falling off the roof. Because the water has nowhere else to go, it will then begin to work its way under the shingles and reach the underside of your roof. From there, the water can enter your attic, leading to soggy insulation, wood rot, water leaks, and eventually mold growth.
How do ice dams form?
After reading about what ice dams are, you may be wondering about one detail, how is the snow able to melt into water but then refreeze before it falls off the roof? After all, if it was warm enough to melt, shouldn’t it be too warm to freeze? The answer lies in your home, and some interesting behind the scenes science.
Due to the cold outside, the inside of your home is likely going to be kept warmer. Mainly, a furnace heats up air and spreads it to the rest of your home. When something increases in temperature, the molecules that make it up are increasing in speed. In the case of air, this movement of molecules causes them to spread out and become less dense. Something with less density will rise above more dense things, like how wood floats on water. As a result, the less dense hot air rises above the more dense cold air. This same property is actually what makes hot air balloons able to fly!
So how does this science fact lead to ice forming on the edge of the roof? Since hot air rises, it will go up as high as it can. In your home, this would eventually lead to the underside of the roof. From there, the hot air warms the underside of the roof until it reaches at least 32 degrees fahrenheit, which causes the snow on top to melt. The melted water flows down the side of the house, with most of it falling off harmlessly, but some water will refreeze on the colder eaves of the roof, where the warm interior air isn’t close enough to melt it. This will continue over a period of time, the ice slowly growing. Eventually, the ice will grow large enough to block the meltwater from falling off, but the water will be kept warm enough to prevent freezing by the passive heat of the home. This creates a small pool of water, and with nowhere else to go it will make its way through the shingles of the roof, leaking into the interior of the home and creating water damage.
Here’s a diagram to help make sense of that information overload:
How to prevent ice dams?
There are multiple ways to prevent ice dams from forming, but their degree of success and difficulty can range quite a bit. The easiest way is to keep your gutters clear of fall debris that can create blockages that help ice dams form. This isn’t a perfect solution, as it only lowers the risk and won’t completely mitigate it. Another simple measure to lower your risk is to use a rake or similar object to remove snow buildup from the edges of the roof, making it easier for the melting snow to fall off.
For more complex solutions, installing heating cables on the roof or gutters will help ensure the snow melts before it can ice over, keeping your house free from ice dams. There are also special venting installations that can be installed in the attic in order to keep the roof the same temperature as the eaves, preventing the warm air inside the home from warming the roof. These methods are more complicated, but they offer much better protection against ice dams.
Despite these prevention measures, there is no way to guarantee an ice dam won’t form. Be sure to regularly check your attic in the winter for any leakage. If you do find any, call our experts at Aloha Restoration! With our plentiful experience in water remediation, we’ll get your home bone-dry in only 48 hours!