The eaves are the edges of the

roof A roof (: roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of tempera ...

which overhang the face of a wall and, normally, project beyond the side of a building. The eaves form an overhang to throw water clear of the walls and may be highly decorated as part of an

architectural style An architectural style is a classification of buildings (and nonbuilding structures) based on a set of characteristics and features, including overall appearance, arrangement of the components, method of construction, building materials used, for ...

, such as the Chinese

dougong ''Dougong'' (Chinese language, Chinese: 斗拱; pinyin: ''dǒugǒng''; lit. 'cap ndblock') is a structural element of interlocking wooden Bracket (architecture), brackets, important in traditional Chinese architecture for both its struct ...

bracket systems.

Etymology and usage

According to the ''

Oxford English Dictionary The ''Oxford English Dictionary'' (''OED'') is the principal historical dictionary of the English language, published by Oxford University Press (OUP), a University of Oxford publishing house. The dictionary, which published its first editio ...

'', ''eaves'' is derived from the

Old English Old English ( or , or ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-S ...

(singular), meaning "edge", and consequently forms both the singular and plural of the word. This Old English word is itself of Germanic origin, related to the German dialect ''Obsen'', and also probably to ''over''. The

Merriam-Webster Merriam-Webster, Incorporated is an list of companies of the United States by state, American company that publishes reference work, reference books and is mostly known for Webster's Dictionary, its dictionaries. It is the oldest dictionary pub ...

dictionary lists the word as ''eave'' but notes that it is "usually used in plural".

Function

The primary function of the eaves is to keep 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 as a form of passive solar building design; the eaves overhang can be designed to adjust the building's solar gain to suit the local climate, the latitude, and orientation of the building. 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 Movement The Arts and Crafts movement was an international trend in the decorative and fine arts that developed earliest and most fully in the British Isles and subsequently spread across the British Empire and to the rest of Europe and America. Initiat ...

influenced the

American Craftsman American Craftsman is an American domestic architectural style, inspired by the Arts and Crafts movement, which included interior design, landscape design, applied arts, and decorative arts, beginning in the last years of the 19th century. ...

tradition, which has very wide eaves with decorative

brackets A bracket is either of two tall fore- or back-facing punctuation marks commonly used to isolate a segment of text or data from its surroundings. They come in four main pairs of shapes, as given in the box to the right, which also gives their n ...

technically called

modillion A modillion is an ornate bracket, more horizontal in shape and less imposing than a corbel. They are often seen underneath a Cornice (architecture), cornice which helps to support them. Modillions are more elaborate than dentils (literally transl ...

s, for which there is not necessarily a real functional need; likewise the Italian-style eaves. The eaves may terminate in a

fascia A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. ...

, 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 A gable is the generally triangular portion of a wall between the edges of intersecting roof pitches. The shape of the gable and how it is detailed depends on the structural system used, which reflects climate, material availability, and aesth ...

s the eaves may extend beyond the gable end wall by projecting the

purlin A purlin (or historically purline, purloyne, purling, perling) is a longitudinal, horizontal, structural member in a roof. In traditional timber framing there are three basic types of purlin: purlin plate, principal purlin, and common purlin. P ...

s and are usually capped off by bargeboards to protect the wall and the purlin ends. The overhang at the gable is referred to as a ''gable'' overhang, as opposed to eave overhang, or they both may be referred to as overhang. The underside of the eaves may be filled with a horizontal

soffit A soffit is an exterior architectural feature, generally the horizontal, aloft underside of the roof edge. Its archetypal form, sometimes incorporating or implying the projection of rafters or trusses over the exterior of supporting walls, is t ...

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.

References

External links

* {{Use dmy dates, date=March 2017 Architectural elements Roofs

Etymology and usage

Function

Design

See also

References

External links