Ice dams form when heat from inside the house warms the roof deck, melting snow that then refreezes at the cold eaves. The fix isn't heat cables or steam — it's eliminating the temperature differential that creates the dam in the first place.
Cold-roof construction does this by separating the conditioned roof from the structural deck with rigid foam insulation and a ventilation channel. The roofing surface stays cold; snow melts evenly or stays frozen until it sheds. No dam, no leak.
The work is labor-intensive. A standard asphalt re-roof is 1–2 days. A vented built-up deck is 7–14 days because we're building four major systems sequentially: insulation, ventilation framing, new decking, and the finish roof. Most contractors aren't equipped to do this work.
