❄️ New Brunswick winters are hard on asphalt shingle roofs. Between snow load, ice accumulation, and repeated freeze-thaw cycles, your roof takes more abuse in one winter than in an entire summer.
One of the most damaging winter phenomena is the ice dam. It forms quietly, causes damage invisibly, and by the time you notice it inside the house, the roof may already have issues that are expensive to fix.
☀️ What is an ice dam?
An ice dam is a ridge of ice that forms at the edge of your roof, usually along the eaves or gutters. It builds up when warm air from inside the attic melts snow on the upper part of the roof. The melted water runs down toward the colder eaves, where it refreezes into a solid band of ice.
As more snow melts and more water runs down, the ice dam grows. Eventually, water pools behind the dam and has nowhere to go but under the shingles. Once water gets under the shingles, it can reach the roof deck, the underlayment, and eventually the interior of your home.
💧 Why freeze-thaw cycles damage shingles
Even without an ice dam, freeze-thaw cycles put stress on asphalt shingles. The GoNano technical white paper explains that asphalt binder aging is driven by oxidation, which makes shingles stiffer and less flexible over time. When stiff shingles go through repeated freeze-thaw cycles, the expansion and contraction puts mechanical stress on the granule-asphalt bond.
Here is what happens in a single freeze-thaw cycle:
- Moisture from rain or melting snow seeps into small cracks or under lifted shingle edges
- Temperatures drop below freezing, causing the moisture to expand as it turns to ice
- The expansion pushes shingle edges up slightly and widens existing cracks
- Temperatures rise, the ice melts, and the cycle repeats
- Each cycle makes the damage slightly worse
Roofs that are already aging, brittle, or losing granules are more vulnerable to this cycle. A shingle that has lost flexibility cannot absorb the movement as well as a newer, more flexible one.
⚠️ Warning signs to watch for during winter
- Large icicles hanging from the eaves (may indicate an ice dam is forming)
- Water stains on ceilings or walls near the roof edge
- Snow that melts in patches on the upper roof but stays frozen at the edges
- Gutters pulled away from the roofline by ice weight
- Shingles that appear lifted or curled after snow melts
If you see any of these signs, consider getting a professional roof assessment before the next winter season. The damage from one bad ice dam season can accelerate aging for the rest of the roof’s life.
🛡️ How preservation helps with winter stress
A roof preservation treatment is not a cure for ice dam damage. Ice dams are caused by attic heat loss and ventilation issues, not by shingle condition alone. Fixing ice dams usually requires improving attic insulation and ventilation.
However, preserving the shingles themselves can help them survive freeze-thaw cycles better. The GoNano white paper reports that ASTM D3161 wind resistance testing showed treated shingles maintained adhesion and passed wind resistance criteria with no tab lift, tearing, or adhesive failure observed under tested conditions. The treatment is designed to support the asphalt binder’s flexibility, which is what helps shingles handle expansion and contraction without cracking.
The key is timing. A preservation treatment should be applied during the dry-weather window, before winter sets in. Once snow and ice are on the roof, treatment cannot be applied until spring.
When to get assessed
If your roof is between 6 and 20 years old and you have noticed any of the warning signs above, consider getting a free assessment before the next winter season. The assessment will tell you whether your roof is still a candidate for preservation, or whether the winter damage has progressed to a point where repair or replacement is the honest recommendation.
Do not wait until spring to find out what winter did to your roof.
Frequently Asked Questions
Can roof treatment prevent ice dams?
No. Ice dams are caused by attic heat loss and poor ventilation, not shingle condition. Treatment helps shingles survive freeze-thaw stress but does not stop ice dams from forming. Fixing ice dams requires insulation and ventilation improvements.
When is the best time to treat my roof before winter?
The treatment should be applied during dry weather, typically between late spring and early fall. It cannot be applied when rain is expected within 12 hours or when temperatures are below freezing.
How do I know if my roof survived winter okay?
Check for lifted or curled shingles, granule buildup in gutters after the snow melts, and any water stains on interior ceilings near exterior walls. A professional assessment can confirm the condition.
Video
Watch: Ice Dams and Freeze-Thaw Damage: What New Brunswick Homeowners Need to Know
Tap the play button to watch this short roof preservation video.
See also
Explore more NanoSeal NB resources and updates:
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