Eaves are the horizontal section of a roof that extends beyond the exterior wall of a structure.
Eaves are the horizontal section of a roof that extends beyond the exterior wall of a structure. The sloped connection between a gable roof or shed and an exterior wall is called a rake. Building eaves provide protection for buildings. The overhang created by the eaves prevents rain, snow, and other debris from falling directly down the side of the building and causing damage to the siding or foundation.
In addition to their mundane function, roof overhangs have historically been used as architectural features. In Dutch colonial houses, the lower ends of the flared roof eaves curve up and away from the roof, creating a silhouette reminiscent of traditional Dutch caps. Frank Lloyd Wright used wide, elongated eaves in his prairie-style residential homes to create flowing lines seemingly connected to the land. Traditional Asian architecture of the Zhou period took advantage of the wide eaves of leaning buildings to build the intricate painted designs, as is common in pagodas.
There are four basic types of eaves: exposed, soffit, recessed, and shortened. At an exposed eave, the finished underside of the roof and its supporting beams are visible from below. Soffit eaves add a trim plate, or soffit, that connects the bottom edge of the eave to the side of the building at a 90-degree angle. This creates a smooth surface when viewed from below. A boxed eave also wraps around the roof joists when viewed from below, but meets the side of the building at the same angle as the roof itself. A shortened eave is cut almost perpendicular to the side of the house.
Eave details for exposed, soffit and boxed eave types include vents to prevent overheating during hot weather and condensation leading to rot during cold/humid weather. Eaves are installed under the roofing material and wrap around the edge of the eaves to prevent wind and water damage. This is especially important when the edges of the eaves meet the gable or cornice.
Over time, the word eaves also came to mean the enclosed space between the intersection of the roof and the internal and external walls of a building. This occurs in buildings where part or all of the roof is parallel rather than perpendicular to the roof, creating a sloped roof, ending at some point in a partial wall called a knee wall. The space between the knee wall and the outside wall is commonly called the eaves and is most often used for storage. This type of eaves is common in traditional New England farmhouses and capes.
