What roofing feature is commonly created by the refreezing of meltwater?

An ice dam is a roofing issue that frequently arises in cold climates and is caused by the refreezing of meltwater. When snow on the roof melts due to warm interior temperatures or direct sunlight, the water flows down to the cooler edges of the roof, where it can refreeze. This process can create a barrier at the eaves, preventing water from draining off the roof. As more meltwater accumulates behind this barrier, it can lead to potential leaks and water damage inside the building.

This phenomenon illustrates the importance of proper insulation and ventilation in roofing systems. Maintaining an even temperature across the roof can help prevent the melt and refreeze cycle, ultimately reducing the risk of ice dams. Understanding this mechanism is crucial for anyone involved in roofing practices, especially in areas prone to winter weather.