Roof Icicles Ice Dams

Thick ridges of solid ice that build up along the eaves.

Roof icicles ice dams.

It s this very melting and refreezing process that causes ice dams in the first place. Poor ventilation and temperature control in the attic can also cause ice dams. Small icicles along the edge of your roof. 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. 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. And only two feet of snow buildup on a roof can cause enough stress for the entire structure to collapse.

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. One of the main safety concerns when it comes to winter weather systems is the buildup of snow and ice on roofs. For an ice dam to form there must be snow on the roof. 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.

When snow accumulates on a rooftop an unevenly heated attic can melt pockets of snow high on. The higher surfaces of the roof s surface must be above 32 f and lower surfaces below 32 f. Heat loss from a house snow cover and outside temperatures interact to form ice dams. That s because the same conditions that allow icicles to form snow covered roofs and freezing weather also lead to ice dams.

This scenario is often the result of a warm attic. If the icicles hanging off your roof are an inch or longer you probably have an ice dam on your hands. 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. But if you see icicles hanging from the edge of your roof it may be a sign of an ice dam.

Icicles don t always mean ice dams. Ice dams and icicles form when the snow melts runs down your roof and refreezes near the edge. When icicles grow large and have a long way to fall they can cause serious injury and even death.