The intersection of two or three
barrel vaults produces a
rib vault or
ribbed vault when they are edged with an
armature of piped masonry often carved in decorative patterns; compare
groin vault, an older form of vault construction. While the mechanics of the weight of a groin vault and its transmission outwards to the supporting pillars remained as it had been, the new use of rib vaults demonstrates the skill of the masons and the grandeur of the new ideas circulating at the introduction of
Gothic architecture in the end of the eleventh century. This technique was new in the late eleventh century, for example in the roofs of the choir side aisles at
Durham Cathedral. Ancestors of the Gothic rib vault in the
Romanesque vaults can be found at
Caen and
Durham, both sites of early Gothic constructions, and elsewhere.