Ice damming begins when roof snow piles up on your roof and the outside temperatures remain below the freezing point of water. The low temperatures mean that the snow doesn’t melt from above, while at the same time, heat being lost from inside the house begins to melt the snow from below. As the bottom of the roof snow layer melts, a thin film of water begins to form between the top of the roofing and the underside of the snow. This water runs down from the top of the roof, beneath the snow, until it reaches the eaves. The melting ice or snow will then re-freeze into a solid ice dam along the eaves.

The water can also work itself up under the shingles. This can lift and damage them as the water freezes. When the outside temperatures eventually rise again, the ice melts and water is able to get inside the house. The water can cause a considerable amount of damage to the attic framing as well as the insulation and the drywall in a home. Often you’re not able to see the damage from the outside of your home as it is hidden behind walls or in the attic. By the time water starts to flow inside your home, you already have a major catastrophe on your hands.

In addition, toxic mold can enter your home due to the damage caused by the ice dam and subsequent leaky roof. This is an obvious health risk for anyone of any age living in the home.