vault

Some of the many different types of vault.

In architecture, a continuous arch of brick, stone, or concrete, forming a self-supporting roof over a building or part of a building; also a vaulted structure, for example under a street pavement.

Of the many different types of vault, the barrel vault or tunnel vault is the simplest form of semi-cylindrical ceiling, consisting of a continuous line of semicircular or pointed vaults. Supporting walls usually require buttresses to contain the thrust of the vault.

The fan vault, characteristic of Gothic architecture, is composed of a number of intersecting sections of cones, which are often highly decorated. The groin vault is formed by the intersection of barrel vaults running at right angles to each other.

Early history The principle of vaulting was known in Babylonia and Egypt 6000 years ago, but was rapidly developed by the Romans, who used concrete; by the Sassanid rulers of Persia in the 6th–7th centuries AD using brickwork; and by medieval builders throughout Europe. The Romans used barrel vaults or tunnel vaults; their barrel vaults were made of concrete and were massively thick.

Romanesque and early Gothic vaulting During the Romanesque period vaults were built of masonry without concrete and were less massive; they were further lightened by the introduction of stone ribs, carrying a thin stone ‘web’, just as the steel ribs of an umbrella support the thin cover. The resulting vault, however, also assumed the convex shape of an umbrella. This led to various difficulties, especially where the nave of a church was twice the width of each aisle, because the wide round arch of the nave was far taller than the narrow arches over the aisles. In the early Gothic period, however, the introduction of pointed arches solved this problem; for they could be made more or less pointed to suit the varying widths of nave and aisles, making it possible to construct a vaulted roof of which the top (or ‘crown’) was level at the ridge.

Later Gothic vaulting Vaulting grew progressively more complicated during the later Gothic period, as intermediate (‘lierne’) ribs were added, and the thickness of the stone ‘web’ was reduced to 15 cm/6 in or so, while the use of massive buttresses enabled walls between the buttress to be much thinner, and to be pierced over much of their surface by great windows of stained glass. Thus a late-Gothic vaulted building became a skeleton of stone ribs and buttresses. Fan vaulting, peculiar to England and introduced during the last phase of Gothic, went even farther; and elaborate but superfluous carved stone pendants were hung to the underside of the vaulting for purely ornamental purposes. The conoidal underside of the vault was carved into tracery, thus producing the effect of a fan when seen from below.