Soffit

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Eaves of a house in Northern Australia. The white underside would be referred to as a soffit. In this example the soffit is fixed to the slope of the rafters. The dark grey fascia boards form the outer edge and have a groove to receive the soffit lining sheets which cover the rafter tails. Eaves-lining.jpg
Eaves of a house in Northern Australia. The white underside would be referred to as a soffit. In this example the soffit is fixed to the slope of the rafters. The dark grey fascia boards form the outer edge and have a groove to receive the soffit lining sheets which cover the rafter tails.
Boxed in soffit on a house in Northern Florida, United States. In this example the soffit material is 12 inches wide and made from center lanced U groove perforated sections of vinyl in a return fashion and fixed to the bottom chord of a truss roofing system extending beyond the exterior wall. View Of Soffit.jpg
Boxed in soffit on a house in Northern Florida, United States. In this example the soffit material is 12 inches wide and made from center lanced U groove perforated sections of vinyl in a return fashion and fixed to the bottom chord of a truss roofing system extending beyond the exterior wall.
Interior soffit box providing attachment points for kitchen ventilation hoods. Soffit box example with kitchen vent hoods.jpg
Interior soffit box providing attachment points for kitchen ventilation hoods.
Four images of a soffit being built to hide a retrofitted ventilation duct. Improvised interior soffit to hide a vent duct.jpg
Four images of a soffit being built to hide a retrofitted ventilation duct.

A soffit is an exterior or interior architectural feature, generally the horizontal, aloft underside of any construction element. Its archetypal form, sometimes incorporating or implying the projection of beams, rafters or trusses over the exterior of supporting walls, is the underside of eaves (to connect a supporting wall to projecting edge(s) of the roof). The vertical band at the edge of the roof is called a fascia.

Contents

Etymology

The term soffit is from Italian : soffitto, formed as a ceiling; and directly from suffictus for suffixus, Latin : suffigere, to fix underneath).

Soffits in homes and offices

In architecture, soffit is the underside (but not base) of any construction element.

Examples include:

DescriptionMore precise synonym
undersurface or under-face of any overhanging section of a roof eave
underside of a cornice
underside of a flight of stairs, under the classical entablature
framework-filled area beneath kink of a chimneyundercroft of chimney
wall into which loudspeakers are mounted in a recording studiowall with speaker recesses
curvature of e.g. plasterwork to fill the space above the kitchen cabinets, at the corner of the ceiling and wall coving (interior design)
underside of office ceiling of tiles (often gypsum) suspended, fastened or bonded to a grid system attached to the walls and/or ceilingfalse/suspended ceiling (tiles/grid) or dropped ceiling
underside of an arch or architrave (whether supported by piers or columns)underarches
lower (usually false) ceiling area to mask and allow egress of upper end of ventilation hood(s)/flues [1] false ceiling/lower ceiling beneath (multi-light/surround) lantern/raised skylight/dome/sloped upper ceiling

Under the eaves of a roof

In foremost use soffit is the first definition in the table above. In spatial analysis, it is one of the two necessary planes of any (3-dimensional) optionally built area, eaves, which projects, for such area to be within the building's space.

In two-dimensional face analysis it is a discrete face almost always parallel with the ground that bridges the gap(s) between a building's siding (walls) and either: their parallel extraneous plane (fascia) where such exists; or where no such plane, a point along (or the abrupt end of) the roof's outer projection (overhang). Soffits and fascias are archetypally screwed or nailed to rafters known as lookout rafters or lookouts for short, their repair being often undertaken simultaneously. A parapet wall or cornice tend to preclude eaves, as an alternate design, both favouring flat roofs and weather-proof walls. Very pronounced overhangs (eaves) are characteristic to European architecture to shield the walls from rain, sleet and snow such as Swiss chalet style, Dutch, Romanian, and Tudor architecture.

Soffit exposure profile (from wall to fascia) on a building's exterior can vary from a few centimetres (2–3 inches) to 3 feet or more, depending on construction. It can be non-ventilated or ventilated, to prevent condensation. A grill that covers the venting opening on the bottom of the soffit is called a soffit vent. A soffit joist can be added to the framework instead of or in addition to lookouts.

See also

Related Research Articles

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In architecture, a cornice is generally any horizontal decorative moulding that crowns a building or furniture element—for example, the cornice over a door or window, around the top edge of a pedestal, or along the top of an interior wall. A simple cornice may be formed just with a crown, as in crown moulding atop an interior wall or above kitchen cabinets or a bookcase.

<span class="mw-page-title-main">Entablature</span> Architectural element

An entablature is the superstructure of moldings and bands which lies horizontally above columns, resting on their capitals. Entablatures are major elements of classical architecture, and are commonly divided into the architrave, the frieze, and the cornice. The Greek and Roman temples are believed to be based on wooden structures, the design transition from wooden to stone structures being called petrification.

<span class="mw-page-title-main">Rafter</span> Supporting structural member in roof construction

A rafter is one of a series of sloped structural members such as steel beams that extend from the ridge or hip to the wall plate, downslope perimeter or eave, and that are designed to support the roof shingles, roof deck, roof covering and its associated loads. A pair of rafters is called a couple. In home construction, rafters are normally made of wood. Exposed rafters are a feature of some traditional roof styles.

<span class="mw-page-title-main">Eaves</span> Protruding structure

The eaves are the edges of the roof 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, such as the Chinese dougong bracket systems.

<span class="mw-page-title-main">Knee wall</span>

A knee wall is a short wall, typically under three feet in height, used to support the rafters in timber roof construction. In his book A Visual Dictionary of Architecture, Francis D. K. Ching defines a knee wall as "a short wall supporting rafters at some intermediate position along their length." The knee wall provides support to rafters which therefore need not be large enough to span from the ridge to the eaves. Typically the knee wall is covered with plaster or gypsum board.

<span class="mw-page-title-main">Bargeboard</span> Architectural element of a gable roof

A bargeboard or rake fascia is a board fastened to each projecting gable of a roof to give it strength and protection, and to conceal the otherwise exposed end grain of the horizontal timbers or purlins of the roof. The word bargeboard is probably from the Medieval Latin bargus, or barcus, a scaffold, and not from the now obsolete synonym vergeboard.

<span class="mw-page-title-main">Attic</span> Space or room below a pitched roof of house or other building.

An attic is a space found directly below the pitched roof of a house or other building; an attic may also be called a sky parlor or a garret. Because attics fill the space between the ceiling of the top floor of a building and the slanted roof, they are known for being awkwardly shaped spaces with difficult-to-reach corners and often exposed rafters.

This page is a glossary of architecture.

<span class="mw-page-title-main">Domestic roof construction</span>

Domestic roof construction is the framing and roof covering which is found on most detached houses in cold and temperate climates. Such roofs are built with mostly timber, take a number of different shapes, and are covered with a variety of materials.

<span class="mw-page-title-main">Fascia (architecture)</span> In architecture, a plain horizontal frieze or band

Fascia is an architectural term for a vertical frieze or band under a roof edge, or which forms the outer surface of a cornice, visible to an observer.

<span class="mw-page-title-main">Rain gutter</span> Component of a water discharge system

A rain gutter, eavestrough, eaves-shoot or surface water collection channel is a component of a water discharge system for a building. It is necessary to prevent water dripping or flowing off roofs in an uncontrolled manner for several reasons: to prevent it damaging the walls, drenching persons standing below or entering the building, and to direct the water to a suitable disposal site where it will not damage the foundations of the building. In the case of a flat roof, removal of water is essential to prevent water ingress and to prevent a build-up of excessive weight.

<span class="mw-page-title-main">Geison</span>

Geison is an architectural term of relevance particularly to ancient Greek and Roman buildings, as well as archaeological publications of the same. The geison is the part of the entablature that projects outward from the top of the frieze in the Doric order and from the top of the frieze course of the Ionic and Corinthian orders; it forms the outer edge of the roof on the sides of a structure with a sloped roof. The upper edge of the exterior often had a drip edge formed as a hawksbeak molding to shed water; there were also typically elaborate moldings or other decorative elements, sometimes painted. Above the geison ran the sima. The underside of the geison may be referred to as a soffit. The form of a geison is often used as one element of the argument for the chronology of its building.

<span class="mw-page-title-main">Plan (drawing)</span>

Plans are a set of drawings or two-dimensional diagrams used to describe a place or object, or to communicate building or fabrication instructions. Usually plans are drawn or printed on paper, but they can take the form of a digital file.

<span class="mw-page-title-main">Multiview orthographic projection</span>

In technical drawing and computer graphics, a multiview projection is a technique of illustration by which a standardized series of orthographic two-dimensional pictures are constructed to represent the form of a three-dimensional object. Up to six pictures of an object are produced, with each projection plane parallel to one of the coordinate axes of the object. The views are positioned relative to each other according to either of two schemes: first-angle or third-angle projection. In each, the appearances of views may be thought of as being projected onto planes that form a six-sided box around the object. Although six different sides can be drawn, usually three views of a drawing give enough information to make a three-dimensional object. These views are known as front view, top view and end view. Other names for these views include plan, elevation and section. When the plane or axis of the object depicted is not parallel to the projection plane, and where multiple sides of an object are visible in the same image, it is called an auxiliary view.

<span class="mw-page-title-main">Lookout (architecture)</span>

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.

<span class="mw-page-title-main">Hidden roof</span> Type of roof

The hidden roof is a type of roof widely used in Japan both at Buddhist temples and Shinto shrines. It is composed of a true roof above and a second roof beneath, permitting an outer roof of steep pitch to have eaves of shallow pitch, jutting widely from the walls but without overhanging them. The second roof is visible only from under the eaves and is therefore called a "hidden roof" while the first roof is externally visible and is called an "exposed roof" in English and "cosmetic roof" in Japanese. Invented in Japan during the 10th century, its earliest extant example is Hōryū-ji's Daikō-dō, rebuilt after a fire in 990.

<span class="mw-page-title-main">Roofline</span>

Roofline is used to describe the fascia, soffits, bargeboards and antefixes that forms the frontage immediately below the roof and the eaves of many homes and buildings. These are traditionally made from wood, but can be made of a variety of different materials, including plastic, such as polyvinyl chloride.

<span class="mw-page-title-main">Hip roof</span> Type of roof where all sides slope downwards to the walls

A hip roof, hip-roof or hipped roof, is a type of roof where all sides slope downwards to the walls, usually with a fairly gentle slope. Thus, a hipped roof has no gables or other vertical sides to the roof.

<span class="mw-page-title-main">Temora Post Office</span> Historic site in New South Wales, Australia

Temora Post Office is a heritage-listed post office at 173 Hoskins Street, Temora, New South Wales, Australia. It was added to the Australian Commonwealth Heritage List on 8 November 2011.

References

  1. "Range Hood Installation Under Sloped / High Ceiling". Futuro Futuro. Retrieved 15 November 2012.