[...] Its origins are not clear. Whereas the groined vault is one of the great Roman vaults, the cross-ribbed one is not at all related to the building techniques of the Roman Empire. In the early Middle Ages, the tradition of building groined vaults is prolonged by the monks who were at that moment building their monasteries in the deep valleys of Europe. The Romanesque vaults were thick stonemasonry shells bound with lime mortar which required, in order to be built, important wooden centerings on which to lay this lime and pebble conglomerate up to its hardening. They were small vaults, frequently meant for the churches’ aisles. [...]