What Causes Ice Damming

Heat loss from a house, snow cover and outside temperatures interact to form ice dams. … The snow on a roof surface that is above freezing will melt. As water flows down the roof it reaches the portion of the roof that is below 32F and freezes. This causes the ice dam.

How do I prevent ice dams on my roof?

1. Ventilate Eaves And Ridge. A ridge vent paired with continuous soffit vents circulates cold air under the entire roof. …
2. Cap the Hatch. …
3. Exhaust to the Outside. …
4. Add Insulation. …
5. Install Sealed Can Lights. …
6. Flash Around Chimneys. …
7. Seal and Insulate Ducts. …
8. Caulk Penetrations.

Is ice damming normal?

Temperatures can hold below freezing during the day and during the night, but ice dams can continue to form if the radiant heat from the sun manages to melt the snow on your roof, despite the ambient temperature being below freezing. That’s just bad luck, and there’s not much you can do.