What Are Building Eaves in Construction?
What Are Building Eaves in Construction?
Building eaves are the overhanging edges of a roof that extend beyond the walls of a building. They serve decorative and practical purposes, adding visual interest to the building’s exterior and providing shade and protection from the elements.
Eaves are typically composed of the soffit, the underside of the eaves, and the fascia, the board along the roof’s edge. The fascia is used to mount gutters and encloses the roof. Eaves are essential features of a building’s roof and contribute to the overall appearance and function of the structure.
The pitch of the roof determines the width of the building eaves. A steep pitch will result in a narrow eave, while a wide pitch will result in a wide eave.
To maximize protection from the sun’s heat, wood eaves are often used on windows facing north and should be 45% of the window’s height. Eaves are attached to the roof’s edge that extends beyond the siding of the building.
Types Of Eaves used in Roofing
Eaves are the edges of a roof that extend beyond the walls of a building. There are two main parts of an eave: soffits and fascia boards.
Soffits are located beneath the roof overhang and act as a covering for the attic, while fascia boards are the trim between the roof and soffit that provide support for the roof and gutter system.
There are four basic types of eaves: exposed, soffited, boxed-in, and abbreviated. Exposed eaves have visible rafters and roof undersides, soffited eaves have a soffit board that connects the overhang to the side of the building at a perpendicular angle, and boards or moldings encase boxed-in eaves.
They are joined to the side of the structure at the same angle as the roof pitch, and abbreviated eaves have little overhang and provide protection from the elements. The type of eave used can vary based on the style of architecture.
Functions Of Building Eaves
Building eaves serve several vital purposes. Their primary function is to keep rainwater from coming into contact with the walls of the building and prevent water from entering the point where the roof meets the wall.
In addition to these water-related functions, eaves can protect pathways around the building from rain, help prevent foundation erosion, and reduce the amount of rainwater splashing onto the walls.
Another function of eaves is to regulate the amount of solar energy that enters the building, which can be done through design and orientation to suit the local climate and latitude. Eaves may also provide shade and shelter for openings used for ventilation in the roof space.
Design Of Building Eaves
The design of the eaves of a building can be influenced by aesthetic, traditional, or decorative considerations rather than just practical needs. Some examples of this are the wide eaves with decorative brackets found in the American Craftsman tradition and the Italian-style eaves.
The eaves may have a board called a fascia running under the tiles or roof sheets to protect the exposed rafter ends and provide a place to attach gutters. At the roofs, the eaves may extend beyond the end wall and be capped off by bargeboards to protect the wall, and the purlin ends.
The underside of the eaves may have a horizontal soffit, which can be decorative but also seal the gap between the rafters and prevent weather and vermin from entering.
The design of the eaves must also consider local wind speeds, as the overhang can increase the wind load on the roof.
The line on the ground under the outer edge of the eaves is called the eavesdrip or dripline, and in building regulations, it defines the extent of the building and cannot go beyond the property boundary.
