Vaults are curved masonry surfaces for roofs and ceilings, able to give shelter and protection. Fireproof and very durable, they were the only massive constructions available for such purposes before modern reinforced concrete was invented. Vaulted ceilings have often been a major issue in the creation of architectural space—as dominating elements with sculptural quality, and as fascinating constructions, often elegant, sometimes astonishing or even daring, always artful, and requiring and demonstrating great expertise and skill in their design and building. In early stone architecture, vaults built with horizontal circular courses can already be characterized as spatial structures. Since the early Great Civilizations, vaults were constructed with blocks arranged in radial bed joints—they could be built with great economy, with complex shape and adapting to irregular plans, as they are still in modern vernacular architecture, such as in Central Asia or in northern Africa. In Late Antiquity, vaults made with dressed stone show great ability in the geometric design—this art was later resumed both in the Middle East and in European Renaissance architecture. In Imperial Rome, vaults made of concrete reached enormous spans, were robust enough to last many centuries, and could be built virtually in any shape. Vaults of brick or stone masonry or of dressed stonework are among the greatest masterpieces of architecture, including the marvelous vaults in Persian architecture, the high vaults of Gothic cathedrals perfectly balanced upon slender pillars, the magnificent spatial inventions of Baroque vaulting, the great domes, and finally the creation of modern shell structures. By principle, vaults are stable by their shape. Their equilibrium demands curvature, regularly resulting in shapes with complex geometry. Therefore, they are very demanding in design, planning, and construction. Systems of anchoring or abutment have to be devised to contain the lateral thrust, and a shape must be created that enables the stability by counterbalancing the heavy components within the vault. Moreover, the building of the curved shape requires form control during bricklaying, geometric design of the temporary support structure, and, in case of stone structures, the formulation of precise specification for producing the single building elements. Therefore, beyond symbolic values, ideas of space in architecture, and the expertise and virtuosity of planners and builders, vaulted ceilings also reflect the historical development of applied geometry and mechanics. Their study gives an insight to the knowledge society that created the buildings.
From stone masonry to emigrant’s mansions. Changes in vernacular architecture in central Portugal
