Cornice molding is generally any horizontal decorative molding which crowns any building or furniture element: the cornice over a door or window, for instance, or the cornice around the edge of a pedestal. A simple cornice may be formed just with a crown molding.
The function of the projecting cornice is to throw rainwater free of the building’s walls. In residential building practice, this function is handled by projecting gable ends, roof eaves, and gutters. The elimination of the cornice has been important enough in modernist architecture, often simply for demands of style, that elaborate internal drainage systems are provided.
The cornice molding is the set of projecting moldings that crown an entablature along the top edge of a temple or building. The cornice lies above the frieze, which rests on the architrave, all supported by columns.
The sloping cornice, “raking cornice” or “rake board,” is also carried across the top of the triangular pediment, at the gable end of a building. (Image:Arch timpano pantheon.jpg), found on the front of such buildings as the Parthenon, the Acropolis, or Schinkel’s Schauspielhaus. The sloping cornice hangs over the end of the structure supporting the roof. In classical and neoclassical architecture, the sloping cornice uses the same molding profile as the cornice below.
Each of the classic orders has certain characteristic profiles to its cornice:
Geison (Greek: γεῖσον) is a specialist's architectural term, denoting 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 (or sometimes architrave) of the Ionic and Corinthan orders: thus it is simply an equivalent of cornice. In classical Greek architecture the geison 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 (particularly the Hawksbeak molding of the outer edge) is often used as one element of the argument for the chronology of its building.
In the Doric order, the sloped underside of the horizontal geison is decorated with a series of protruding, rectangular mutules aligned with the triglyphs and metopes of the Doric frieze below. Each mutule typically had three rows of six guttae (decorative conical projections) protruding from its underside. The gaps between the mutules are termed viae (roads). The effect of this decoration was to thematically link the entire Doric entablature (architrave, frieze, and geisa) with a repeating pattern of vertically and horizontally aligned architectural elements. Use of the hawksbill molding at the top of the projecting segment is common, as is the undercutting of the lower edge to aid in dispersing rainwater. In order to separate the geison from the frieze visually, there is typically a bed molding aligned with the face of the triglyphs.
A raking geison ran along the top edge of a pediment, on a temple or other structure such as the aedicula of a scaenae frons (theater stage building). This element was typically less decorative than the horizontal geison, and often of a differing profile from the horizontal geison of the same structure. The difference is particularly marked in the Doric order, where the raking geison lacks the distinctive mutules. The raking sima ran over the raking geison as a decorative finish and, essentially, a rain gutter.