is a wall-like barrier at the edge of a roof
. It may serve to prevent unwanted falls over the edge or it may be a defensive, constructional or stylistic feature.
The word comes ultimately from the Italian parapetto (parare = to cover/defend and petto =breast). The German term Brustwehr has the same significance.
Parapets may be plain, embattled, perforated or paneled, which are not mutually exclusive terms.
- Plain parapets are upward extensions of the wall, sometimes with a coping at the top and corbel below.
- Embattled parapets may be paneled, but are pierced, if not purely as stylistic device, for the discharge of defensive projectiles.
- Perforated parapets are pierced in various designs such as circles, trefoils, quatrefoils.
- Paneled parapets are ornamented by a series of panels, either oblong or square, and more or less enriched, but not perforated. These are common in the Decorated and Perpendicular periods.
Parapets surrounding roofs are extremely common in London. This dates from the Building Act of 1707 which banned projecting wooden eaves in the cities of Westminster and London as a fire risk. Instead an 18-inch brick parapet was required, with the roof set behind. This was continued in many Georgian houses, as it gave the appearance of a flat roof which accorded with the desire for classical proportions.
Parapets on bridges and other highway
structures (such as retaining walls
) prevent users from falling off where there is a drop. They may also be meant to restrict views, to prevent rubbish passing below, and to act as noise barriers
Bridge parapets may be made from any material, but structural steel, aluminium, timber and reinforced concrete are common. They may be of solid or framed construction.
In European standards, parapets are defined as a sub-category of "vehicle restraint systems" or "pedestrian restraint systems".