Ice Management and De-Icing
Ice dams are one of the most damaging winter phenomena for Ontario homeowners. A serious ice dam can cause water to back up under shingles, saturate insulation, damage drywall and ceilings, and promote mold growth — all from the outside in.
Understanding ice dam formation: ice dams form when the upper portion of a roof is above freezing (melting snow) while the eave overhangs are below freezing (exterior temperature). The meltwater runs down the roof slope, hits the cold eave, and freezes, building up a dam of ice.
Best Practices for Ontario Winters
What makes the upper roof warm? Heat loss from the living space below. Every gap in your air barrier — around pot lights, where walls meet the ceiling, around plumbing or electrical penetrations — lets warm air into the attic, warming the roof deck above.
Primary prevention: air sealing. Sealing air leaks from the living space into the attic is more effective than adding insulation alone. Hire an energy auditor to identify the leak points, then seal with spray foam and rigid insulation before adding insulation on top.
Professional Snow and Ice Control
Secondary prevention: adequate ventilation. Proper attic ventilation (continuous soffit intake + ridge exhaust) keeps the attic cold by exhausting any heat that does enter. The goal is an attic temperature as close to outdoor temperature as possible.
Insulation levels: Ontario Building Code requires R-60 insulation for attics in new construction. Many older KW homes have R-20 to R-30. Upgrading attic insulation reduces heating costs and ice dam risk simultaneously — one of the highest-ROI home improvements in Ontario.
Emergency removal: if ice dams form and water is actively entering the home, professional removal with steam is the safest method. Steam melts ice without the impact damage that hammers or chippers cause to shingles. Do not apply chloride-based ice melts to your roof — they stain and degrade roofing materials over time.
Key Takeaways
- Ice dams are one of the most damaging winter phenomena for Ontario homeowners.
- What makes the upper roof warm?...
- Secondary prevention: adequate ventilation.
- D&D Snow Services serves Kitchener, Waterloo, Cambridge, Guelph and surrounding areas
- Get a free no-obligation quote — call or book online anytime
Sources & References
- Ontario Building Code — Relevant Standards & Guidelines
- D&D Snow Services field experience across Waterloo Region
