Roof Icicles Ice Dams

It s this very melting and refreezing process that causes ice dams in the first place.

Roof icicles ice dams.

When icicles grow large and have a long way to fall they can cause serious injury and even death. That s because the same conditions that allow icicles to form snow covered roofs and freezing weather also lead to ice dams. Thick ridges of solid ice that build up along the eaves. Icicles hanging along the eaves of your house may look beautiful but they spell trouble.

When snow accumulates on a rooftop an unevenly heated attic can melt pockets of snow high on. Ice dams and icicles form when the snow melts runs down your roof and refreezes near the edge. The problem is these ice dams can force water up under your roof s shingles. Heat loss from a house snow cover and outside temperatures interact to form ice dams.

A dam will grow on the parts of the roof that are below freezing. 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. 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. 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.

An ice dam is a ridge of ice that forms along the edge of your roof. Icicles don t always mean ice dams. Poor ventilation and temperature control in the attic can also cause ice dams. 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.

But if you see icicles hanging from the edge of your roof it may be a sign of an ice dam. One of the main safety concerns when it comes to winter weather systems is the buildup of snow and ice on roofs. The major issue with ice dams on the roof is that they trap the melting water running down from the top of the roof and thereby cause it the melted water to rise up underneath the roofing shingles and eventually seep through the boards and walls inside our homes. This scenario is often the result of a warm attic.

The higher surfaces of the roof s surface must be above 32 f and lower surfaces below 32 f. Nonuniform roof surface temperatures lead to ice dams. If the icicles hanging off your roof are an inch or longer you probably have an ice dam on your hands.