Winter is quickly approaching, and with it, the anticipation of cold weather, cozy mornings, hot cocoa, and blankets of fresh snow. For many people, snow is an exciting morning surprise, but as a homeowner you may have a different reaction. “Is the snow going to be too heavy for my roof? Will the ice harm my roof?” are questions that may come to your mind when you see snow on the forecast.
While roofs are made to protect your home from inclement weather, there are multiple ways that snow and ice can affect your roofing system in the winter months. Understanding these effects can help you address potential issues early on, take steps to add snow and ice roof protection to your home, and allow you to enjoy snowy mornings without second guessing the integrity of your roof.
Stress From Snow Buildup
Rooftop snow accumulation is one of the most important things to watch for after a storm. If heavy snow is left unchecked, it can stress your roof beyond its normal load-bearing capabilities and cause the roof to cave in. Snow weighs roughly seven pounds per cubic foot when dry and fluffy, and twenty pounds per cubic foot when wet and compacted. Ice buildup weighs even more.
Each roof has different load-bearing capabilities, but in general, three feet of snow or two inches of ice are enough to threaten the structural integrity of your roof, and should be removed as soon as possible.
The Freeze-Thaw Cycle
The freeze-thaw cycle can be a devastating scenario for roofs in the aftermath of a cold weather storm. This cycle occurs when daytime temperatures are warm enough to melt the snow on your roof, but overnight temperatures dip back below the point of freezing. These conditions allow melted snow to find its way into small cracks in your roof and then expand as it refreezes.
The expansion forces the small cracks to widen. Repeated freeze-thaw cycles can eventually lead to water intrusion into your attic and home through the cracks, and cause significant water damage. In most cases, an annual roof inspection can catch these cracks. Repairing them early will prevent future damage from happening.
One of the most common causes of winter roof damage are ice dams, which are ridges of ice that form at the edge of a roof that prevent snow melt from draining into the gutters. There are several common causes of ice dams:
Inadequate Insulation: Inadequate insulation allows too much warm air from inside the house to escape into the attic space. This air warms the roofing system enough to increase the surface temperature of the shingles and melt the snow on top of the roof. As the melted snow runs down the roof, it eventually reaches the roof edge, which is not warmed by the attic. The difference in temperature causes the melted snow to refreeze and form an ice dam.
Mild Winter Weather: Ice dams are a risk during warmer winter days because the sun warms the roof and causes the snow to melt. However, when the sun goes down and the temperature drops back below 32 degrees, the snow refreezes. This often happens near the edge of the roof and causes an ice dam.
Flat-pitched roofs: Roofs with a flatter pitch are more prone to ice dams. This is because water isn’t able to run off as quickly as it would on roofs with steeper pitches. That extra time increases the risk of water getting stuck near the edge of the roof and refreezing into an ice dam.
Whenever an ice dam forms at the roof edge, water is unable to drain off of the roof. Since it has nowhere to go, the water gets backed up and forced beneath the shingles, eventually leaking into your attic and home in multiple places. Metal roofs are less susceptible to ice dams than shingle roofs are since snow is able to slide off of metal more easily.
Your gutter system is also susceptible to snow and ice damage. In the aftermath of a heavy storm, excess melted snow or ice can become trapped in your gutter system. When the water refreezes, it expands and can cause gutters to crack, burst, or even separate from your home. Ice-clogged gutters can also lead to backups, and the formation of ice dams, since they don’t allow water to drain properly.
Whether you have a leak caused by an ice dam, or are dealing with ice-clogged gutters, let Cenvar Roofing help you! We are a company of certified roofing professionals with many years of experience repairing snow and ice damaged roofs all winter long. Schedule your free estimate today to start the process. We look forward to serving you!