How Do Ice Dams Damage Roofs?

In winter, heavy snow and cold temperatures reign supreme. To make it worse, most of this snow lands on roofs, leaving them weak or wholly damaged. Aside from putting pressure on your roof, the heavy snow will cause ice dams, leading to leakages. This article explains how ice dams can damage your roof.

What Are Ice Dams and How Do They Form?

Ice dams are pools of water that form on the roof when the snow melts. As you run your heating system to warm your house, some hot air will seep into the top parts of your roof, causing the snow in these areas to melt. But as the melted snow flows down the roof, it freezes and turns into ice, especially when it reaches the more incredible edges of the roof near the eave. The frozen water forms blocks of ice that prevent more melted snow from draining, thus forming ice dams.

Uneven temperatures on your roof are the leading cause of ice dams. The uneven heating of the roof is mainly due to poor attic insulation or ventilation. The heat from your house can escape through the ceiling, heating some parts of your roof. This causes different patches of snow on the roof to melt, creating ice dams in different parts of your roof.

How Ice Dams Can Damage Your Roof

When ice dams form on your roof, they’ll back up and seep through the shingles. As more water gets stuck under the shingles, it’ll soak up the sheathing and the deck, leaving the whole roof weak and susceptible to splintering. This water may also leak into the attic insulation, affecting its performance. Wet attic insulation isn’t as effective as a dry one. It will also allow water to get into the walls and your living area.

When the water gets to the drywall, it will leave noticeable stains and eventually cause the drywall to warp. If your roof is made of wood, it will rot and cave in. Sometimes the blocks of ice will become too heavy, making the edges of your roof susceptible to damage. If these blocks break free and fall, they might damage your gutters and downspouts. The water in your attic will lead to the growth of mold and mildew, which will weaken the roof further and can even cause serious respiratory problems.