vault

Gothic rib vault ceiling of the Saint-Séverin church in Paris Interior elevation view of a Gothic cathedral, with rib-vaulted roof highlighted

In architecture, a vault (French voûte, from Italian volta) is a self-supporting arched form, commonly of stone or brick, serving to cover a space with a ceiling or roof. As in building an arch, a temporary support is needed while rings of voussoirs are constructed and the rings placed in position. Until the topmost voussoir, the keystone, is positioned, the vault is not self-supporting. Where timber is easily obtained, this temporary support is provided by centering consisting of a framed truss with a semicircular or segmental head, which supports the voussoirs until the ring of the whole arch is completed.