Editing Romanesque architecture (section)

====Ribbed vault====
[[Ribbed vault]]s came into general use in the 12th century. In ribbed vaults, not only are there ribs spanning the vaulted area transversely, but each vaulted bay has diagonal ribs, following the same course as the groins in a groin vault. However, whereas in a groin vault, the vault itself is the structural member, in a ribbed vault, it is the ribs that are the structural members, and the spaces between them can be filled with lighter, non-structural material.<ref name =BF307>Banister Fletcher, p. 307</ref>

Because Romanesque arches are nearly always semi-circular, the structural and design problem inherent in the ribbed vault is that the diagonal span is larger and therefore higher than the transverse span.<ref name=BF307/> The Romanesque builders used a number of solutions to this problem. One was to have the centre point where the diagonal ribs met as the highest point, with the infill of all the surfaces sloping upwards towards it, in a domical manner. This solution was employed in Italy at [[San Michele, Pavia]], and [[Sant' Ambrogio, Milan]].<ref name=Toman/>

The solution employed in England was to stilt the transverse ribs, maintaining a horizontal central line to the roof like that of a barrel vault.<ref name=BF307/> The diagonal ribs could also be depressed, a solution used on the sexpartite vaults at both the Saint-Étienne, ([[Abbaye-aux-Hommes]]) and Sainte-Trinité, ([[Église de la Ste.-Trinité, Caen|Abbaye-aux-Dames]]) at Caen, France, in the late 11th and early 12th centuries.<ref name=BF307/>