What Are the Functions of the Eaves on a Home?

Forms

• Eaves are constructed as deep overhangs on homes in warm climates in order to offer cooling shadows for your home’s exterior and to shade the windows when the sun is at its highest; in cooler climates, they are designed as shallow overhangs to allow the sun to help warm a home’s exterior, according to This Old House.com. Eaves with broad overhangs are featured on bungalows and Italianate-style homes.

Function

• Eaves also play a part in the ventilation of some homes. The undersides of the eaves, called soffits, may contain vents that allow an exchange of air between the attic and the outdoors, regulating the temperature of the attic space and helping to reduce humidity. Without such ventilation, your attic’s temperatures may become high enough to endanger your health and the condition of stored items.

Problems

• During the winter months, the eaves remain one of the coldest parts of the roof. When heat enters your attic space, snow and ice melt and run down the roof. When the water reaches the eaves, it freezes in place, forming a sheet of ice called an ice dam. As the ice grows in thickness, the water from subsequent melts has nowhere to go, so it forms a reservoir behind the ice. Trapped higher up on the warmer sections of roof, the water may not re-freeze; it can then seep through cracks in the roof, come up under your shingles and enter your home, causing damage.

Considerations

• The same melting/freezing process that causes ice dams leads to dramatic hanging icicles along your eaves. In this case, water tops the ice dam, running over your gutters and freezing into icicles. While they look lovely and seasonal, large icicles are a danger to passersby and to the structure of your home. As falling chunks of ice can tear away your gutters and break windows, the University of Nebraska-Lincoln Extension recommends removing large icicles to relieve the weight stress on your gutters.