ABSTRACT
The tierceron vault played a fundamental role in the evolution of Gothic from the quadripartite vault, internally formed just by two diagonal ribs, towards the typical late Gothic rib multiplication. Designing a tierceron’s vault plan requires a single decision: determining the tiercerons. For this reason, this work deals with the study of the geometrical properties and the constructive implications of the most frequent tierceron’s vault plan designs, extracted from preserved written sources and from the surveying of relevant cases of existing vaults. They seem to be simple procedures, easy to be reproduced on the elevated platform on which the vault was built.
