Roof Icicles Ice Dams

This scenario is often the result of a warm attic.

Roof icicles ice dams.

Thick ridges of solid ice that build up along the eaves. But if you see icicles hanging from the edge of your roof it may be a sign of an ice dam. This happens when warm air inside your home melts snow on the roof which then refreezes as it reaches the unheated colder eaves when temperatures drop. The problem is these ice dams can force water up under your roof s shingles.

An ice dam is a ridge of ice that forms along the edge of your roof. Ice dams and icicles form when the snow melts runs down your roof and refreezes near the edge. Small icicles along the edge of your roof. Poor ventilation and temperature control in the attic can also cause ice dams.

But they do mean snow is melting on your roof and that some of the runoff is freezing into icicles as it trickles off the edge of your roof. It s this very melting and refreezing process that causes ice dams in the first place. That s because the same conditions that allow icicles to form snow covered roofs and freezing weather also lead to ice dams. When icicles grow large and have a long way to fall they can cause serious injury and even death.

For ice dams to form there must be snow on the roof and at the same time higher portions of the roof s outside surface must be above 32 degrees f freezing while lower surfaces are below 32f. Icicles don t always mean ice dams. For an ice dam to form there must be snow on the roof. Icicles hanging along the eaves of your house may look beautiful but they spell trouble.

One of the main safety concerns when it comes to winter weather systems is the buildup of snow and ice on roofs. And only two feet of snow buildup on a roof can cause enough stress for the entire structure to collapse. The higher surfaces of the roof s surface must be above 32 f and lower surfaces below 32 f. This only occurs when part of your roof warms to above 32 degrees f warm enough to melt the snow while the roof edge remains below freezing.

Heat loss from a house snow cover and outside temperatures interact to form ice dams. When snow accumulates on a rooftop an unevenly heated attic can melt pockets of snow high on. Nonuniform roof surface temperatures lead to ice dams.