Vault is an architectural term for an arched roof or ceiling. Vaults are most commonly made of brick, concrete, or stone. The four main kinds are (1) the barrel vault, (2) the groined vault, (3) the ribbed vault, and (4) the dome.
The barrel vault, the simplest type, is a single continuous unbroken arch in the form of a tunnel. The groined vault is formed by joining two barrel vaults of the same shape at right angles. The lines at which the two vaults meet are called groins. In the ribbed vault, projecting ribs cover the groins, or are placed in decorative patterns elsewhere on the vault’s surface. The dome is a vault in the form of a hemisphere (half sphere) built on a circular base.
