As a homeowner in Burnsville, MN, you’re no stranger to frigid winter temperatures. These cold conditions can cause ice to form around your home, and one of the most damaging consequences is ice dams. If left unchecked, ice dams can lead to significant roof damage. Here’s what you need to know about ice dams and how to prevent them effectively.
What Are Ice Dams?
Ice dams are thick ridges of ice that form along sloped roofs, blocking the natural flow of snowmelt and preventing proper drainage. They are especially common in northern climates, where daytime sun melts snow on the roof, only for it to refreeze overnight as temperatures drop. These formations often develop at roof edges but can also occur in valleys, around skylights, behind dormers, and in other areas where snowmelt gets trapped.
Why Are Ice Dams Problematic?
Ice dams pose a serious risk to your roof by trapping water that would otherwise drain off. As water backs up behind the ice, it seeps under shingles and penetrates the roof’s underlayment and decking. Over time, this trapped moisture can lead to rotting wood, deteriorated insulation, and weakened structural integrity.
In the short term, ice dams can cause leaks in your attic and damage insulation. Materials like fiberglass and cellulose absorb water easily, making them heavier and reducing their ability to regulate indoor temperatures. Waterlogged insulation can also create an ideal environment for mold growth, which may pose health risks for your family. Addressing ice dams promptly is essential to protecting your home’s long-term structural integrity and avoiding costly roofing repairs.
The Most Common Causes of Ice Dams
Ice dams typically form due to uneven roof temperatures. If parts of your roof are warm enough to melt snow while others remain cold, the meltwater will refreeze before it can drain, creating ice buildup. Several factors contribute to this temperature imbalance.
One of the most common causes is an attic that retains too much heat. When warm air escapes from your home into the attic, it rises to the peak of the roof, melting the snow above. As the meltwater travels down the slope, it encounters colder roof edges and refreezes, forming an ice dam.
Certain roof designs and environmental conditions can make ice dams more likely. Roofs with complex designs—such as multiple valleys, dormers, or low slopes—are more prone to ice damming because they create natural obstructions that trap snowmelt. Additionally, if your home is shaded by trees or tall buildings, parts of the roof may remain colder than others, increasing the risk of uneven melting and refreezing.
Fluctuating temperatures play a major role as well. Ice dams do not form all at once; rather, they build up over time. When temperatures hover around freezing and cycle between thawing and refreezing, ice accumulation can worsen, making removal more challenging.
How To Prevent Ice Dams
Preventing ice dams requires addressing the root causes rather than just treating the symptoms. The most effective strategies include removing snow promptly, improving attic insulation and ventilation, and installing heating cables when necessary.
Prompt Snow Removal
One of the most effective ways to prevent ice dams is to remove snow accumulation before it has a chance to melt and refreeze. A roof rake with a telescoping handle is a useful tool for safely clearing snow from the roof’s surface. When using a roof rake, it’s essential to pull snow downward rather than push it upward, as improper technique can loosen or damage shingles.
However, DIY snow removal isn’t always practical, especially after a major storm. Snow left on higher areas of the roof will continue to melt and refreeze, contributing to ice dam formation. In these cases, hiring a professional for snow removal ensures the job is done safely and effectively.
Improve Attic Insulation
Addressing attic temperature is a key factor in preventing ice dams. Ideally, an unfinished attic should remain within a few degrees of the outdoor temperature in winter. If your attic is noticeably warmer, heat from your living spaces is likely escaping into the attic, creating a prime environment for ice dam formation.
The first step in reducing attic heat loss is air sealing. Gaps around ducts, pipes, vents, chimneys, and the attic access hatch should be properly sealed to prevent warm air from leaking into the attic. This process helps maintain a consistent roof temperature and minimizes the risk of ice damming.
Upgrading attic insulation is another effective strategy. The current building code recommends attic insulation with an R-value of 49, but upgrading to R-60 or higher can provide even better temperature regulation. If you have HVAC ductwork running through your attic, insulating the ducts is also crucial. Hot air escaping from uninsulated ductwork can contribute to a warmer attic, making ice dams more likely to form. Proper insulation not only prevents ice dams but also enhances your home’s energy efficiency and reduces heating costs.
Ensure Proper Attic Ventilation
Proper attic ventilation is essential for maintaining stable roof temperatures. Without adequate ventilation, warm air becomes trapped in the attic, increasing the likelihood of ice dams. A professional roof inspection can determine whether your attic has sufficient airflow based on its size and layout.
Improving ventilation often involves installing ridge vents, soffit vents, or both. Ridge vents run along the peak of the roof, allowing warm air to escape, while soffit vents near the eaves draw in cooler air from outside. Together, these components create a balanced ventilation system that helps regulate attic temperatures.
In some cases, a roofer may also install baffles to ensure continuous airflow in hard-to-reach areas. Proper ventilation reduces the likelihood of ice dams by preventing heat buildup and ensuring that snow melts at an even rate across the roof.
Installing Heating Cables
For homes with persistent ice dam issues—especially those with roof areas that remain shaded throughout the day—roof edge and gutter heating cables may be a practical solution. These cables use electric resistance heating to prevent ice dams from forming or to melt channels through existing ice, allowing trapped water to drain.
However, heating cables should be considered a last resort rather than a primary solution. While they can help mitigate ice dams, they increase energy costs and require careful installation to avoid safety hazards. When used incorrectly, they can create localized hot spots on the roof, leading to uneven melting and potential damage to roofing materials. For best results, heating cables should be installed by a professional and used in combination with insulation and ventilation improvements.
Contact Your Local Roofing Experts
At Schmidt Roofing, we have been serving the residents of Burnsville, MN, for over 30 years with expert residential roofing services. We specialize in roof installation, maintenance, and repair, helping homeowners protect their properties from the challenges of Minnesota winters. Our team also provides professional snow removal services to prevent ice dams before they cause damage.
If you’re concerned about ice dams or need expert guidance on improving your roof’s insulation and ventilation, contact us today to schedule an inspection. We’re here to help keep your roof in top condition—no matter how cold it gets.
