Eaves
Encyclopedia
The eaves of a roof
are its lower edges. They usually project beyond the walls of the building to carry rain water away.
The secondary function is to control solar penetration; the eaves overhang can be designed to adjust the building's solar heat gain to suit the local climate, the latitude and orientation of the building, refer to passive solar building design
.
The eaves overhang may also shelter openings to ventilate the roof space.
influenced the American Craftsman
tradition, which has very wide eaves with decorative brackets
, for which there is not necessarily a real functional need; likewise the Italianate eaves, shown on the right.
The eaves may terminate in a fascia
, a board running the length of the eaves under the tiles or roof sheets to cap off and protect the exposed rafter ends and to provide grounds on which to fix gutters. At the gable
s the eaves may extend beyond the gable end wall by projecting the purlin
s and are usually capped off by bargeboard
s to protect the wall and the purlin ends.
The underside of the eaves may be filled with a horizontal soffit
fixed at right angles to the wall, the soffit may be decorative but it also has the function of sealing the gap between the rafters from vermin and weather.
Eaves must be designed for local wind speeds as the overhang can significantly increase the wind loading on the roof.
The line on the ground under the outer edge of the eaves is the eavesdrip
, or dripline, and in typical building planning regulations defines the extent of the building and cannot oversail the property boundary.
Roof
A roof is the covering on the uppermost part of a building. A roof protects the building and its contents from the effects of weather. Structures that require roofs range from a letter box to a cathedral or stadium, dwellings being the most numerous....
are its lower edges. They usually project beyond the walls of the building to carry rain water away.
Etymology
"Eaves" is derived from Old English and is both the singular and plural form of the word.Function
The primary function of the eaves is to throw rain water off the walls and to prevent the ingress of water at the junction where the roof meets the wall. The eaves may also protect a pathway around the building from the rain, prevent erosion of the footings and reduce splatter on the wall from rain as it hits the ground.The secondary function is to control solar penetration; the eaves overhang can be designed to adjust the building's solar heat gain to suit the local climate, the latitude and orientation of the building, refer to passive solar building design
Passive solar building design
In passive solar building design, windows, walls, and floors are made to collect, store, and distribute solar energy in the form of heat in the winter and reject solar heat in the summer...
.
The eaves overhang may also shelter openings to ventilate the roof space.
Design
Aesthetic, traditional or purely decorative considerations may prevail over the strictly functional requirements of the eaves. The Arts and Crafts MovementArts and Crafts movement
Arts and Crafts was an international design philosophy that originated in England and flourished between 1860 and 1910 , continuing its influence until the 1930s...
influenced the American Craftsman
American Craftsman
The American Craftsman Style, or the American Arts and Crafts Movement, is an American domestic architectural, interior design, landscape design, applied arts, and decorative arts style and lifestyle philosophy that began in the last years of the 19th century. As a comprehensive design and art...
tradition, which has very wide eaves with decorative brackets
Bracket (architecture)
A bracket is an architectural member made of wood, stone, or metal that overhangs a wall to support or carry weight. It may also support a statue, the spring of an arch, a beam, or a shelf. Brackets are often in the form of scrolls, and can be carved, cast, or molded. They can be entirely...
, for which there is not necessarily a real functional need; likewise the Italianate eaves, shown on the right.
The eaves may terminate in a fascia
Fascia (architecture)
Fascia is a term used in architecture to refer to a frieze or band running horizontally and situated vertically under the roof edge or which forms the outer surface of a cornice and is visible to an outside observer...
, a board running the length of the eaves under the tiles or roof sheets to cap off and protect the exposed rafter ends and to provide grounds on which to fix gutters. At the gable
Gable
A gable is the generally triangular portion of a wall between the edges of a sloping roof. The shape of the gable and how it is detailed depends on the structural system being used and aesthetic concerns. Thus the type of roof enclosing the volume dictates the shape of the gable...
s the eaves may extend beyond the gable end wall by projecting the purlin
Purlin
In architecture or structural engineering or building, a purlin is a horizontal structural member in a roof. Purlins support the loads from the roof deck or sheathing and are supported by the principal rafters and/or the building walls, steel beams etc...
s and are usually capped off by bargeboard
Bargeboard
Bargeboard is a board fastened to the projecting gables of a roof to give them strength and to mask, hide and protect the otherwise exposed end of the horizontal timbers or purlins of the roof to which they were attached...
s to protect the wall and the purlin ends.
The underside of the eaves may be filled with a horizontal soffit
Soffit
Soffit , in architecture, describes the underside of any construction element...
fixed at right angles to the wall, the soffit may be decorative but it also has the function of sealing the gap between the rafters from vermin and weather.
Eaves must be designed for local wind speeds as the overhang can significantly increase the wind loading on the roof.
The line on the ground under the outer edge of the eaves is the eavesdrip
Eavesdrip
The eavesdrip is the width of ground around a house or building which receives the rain water dropping from the eaves.This is sometimes also known as the eavesdrop, but an eavesdrop is also a small, not very visible hole in a building used to listen in on the conversation of people awaiting...
, or dripline, and in typical building planning regulations defines the extent of the building and cannot oversail the property boundary.
See also
- Eaves (disambiguation)Eaves (disambiguation)Eaves may refer to:* Eaves, the edges of a roof* Eaves , a surname* Eaves, Lancashire, a place in England, United Kingdom...
- EavesdripEavesdripThe eavesdrip is the width of ground around a house or building which receives the rain water dropping from the eaves.This is sometimes also known as the eavesdrop, but an eavesdrop is also a small, not very visible hole in a building used to listen in on the conversation of people awaiting...
- EavesdroppingEavesdroppingEavesdropping is the act of secretly listening to the private conversation of others without their consent, as defined by Black's Law Dictionary...
- ChhajjaChhajjaA chhajja is the projecting or overhanging eaves or cover of a roof, usually supported on large carved brackets. It was used extensively by Hindus for thousands of years, and then more recently borrowed by the invading Muslim empires into the common vocabulary of “Mughal Architecture."It forms...
- RainheadRainheadA leader head is a device used in roof plumbing to capture stormwater runoff from the rain guttering of a building. While, generally speaking, such a device is known as either a leader head or a conductor head within the fields of architecture, building design and construction, it may be known as...
- GargoyleGargoyleIn architecture, a gargoyle is a carved stone grotesque, usually made of granite, with a spout designed to convey water from a roof and away from the side of a building thereby preventing rainwater from running down masonry walls and eroding the mortar between...
- SoffitSoffitSoffit , in architecture, describes the underside of any construction element...
- Lookout (architecture)Lookout (architecture)A lookout, lookout rafter or roof outlooker is a wooden joist that extends in cantilever out from the exterior wall of a building, supporting the roof sheathing and providing a nailing surface for the fascia boards. When not exposed it serves to fasten the finish materials of the eaves....