Kereszboltozatok

Kereszboltozatok, or keresztboltozat, are architectural vaults formed by the perpendicular intersection of two barrel vaults at right angles. The intersection creates groins—edge lines that run along the vault’s surface and divide it into four arched panels. The vault’s weight is carried to the supporting piers or columns at the corners of each bay, allowing the walls between supports to be thinner or to accommodate openings.

Structurally, the cross vault distributes loads more efficiently than a single barrel vault, enabling longer bays and larger interior spaces within the same exterior footprint. The groins define a clear geometric pattern and can be plain or decorated with coffers or sculptural details. In many medieval buildings, the cross vault is used where a rectangular plan is subdivided into square or nearly square modules, providing a rational and robust roofing system for churches, halls, and secular structures.

Historically, cross vaults appeared in late antiquity and remained common throughout Romanesque architecture, continuing into Gothic buildings. In Romanesque churches they often mark the main bays, while Gothic builders sometimes enhanced them with ribs to form ribbed groin vaults, combining the traditional cross-vault concept with the expressive language of rib vaulting. In Hungarian architectural terminology, kereszboltozatok describe this form as a major type of vault, distinguishing it from simple barrel vaults and from later rib vault configurations.