What is a Roof Ice Dam?

An ice dam is a ridge of ice that forms at the edge of a roof and prevents melting snow (water) from draining off the roof. The water that backs up behind the dam can leak into a home. This water will cause damage to walls, ceilings, insulation, and other areas.

What causes ice dams?

Ice dams form due to many things:

• heat loss from your house
• snow accumulation on the roof
• cooling temperatures

How does an Ice Dam form?

The snow on higher parts of the roof surface begins to melt and water flows down the roof towards the gutter. If the lower parts of the roof are colder than the higher part, the water will start to freeze. The more this happens, the ice starts to build up more and more until you have an ice dam.

The ice dam grows from the melting snow above it. It will limit itself to the portions of the roof that are on the average below 0°.

Then the water above the ice dam starts to back up behind the ice dam and remains a liquid. This water finds cracks and openings in the exterior roof covering. The water then flows into the attic space. From the attic, it could flow anywhere in the house. Into exterior walls or through the ceiling insulation and stain the ceiling finish.

Preventing and dealing with ice dams

Prevent ice dams by controlling the heat loss from the home.

It’s also important to inspect your roof from time to time and watch for snow build up.

Fix air leaks and add more insulation

Make the ceiling airtight. From the attic space, caulk around pipes and chimney structures that go from your living space into the attic. Once this is complete, consider adding more insulation into your attic space.

Hiring a professional is the best solution. The right insulation professional will make sure you also have proper air flow

After sealing air leakage. Consider increasing the ceiling/roof insulation. This will help cut down on heat loss.