From the 19th century onwards, with the introduction of new materials, such as iron and reinforced concrete, there was a significant change in construction, and vaults were gradually abandoned. However, before the Modern Movement, in the age of historicism, vaults were still used in churches and representative buildings. In the handbooks and treatises of the time, the more traditional techniques were included alongside the more modern ones and it is not uncommon, even well into the 20th century, to find chapters devoted to the construction of vaults. The search for economy in construction became particularly necessary in the post-war periods when many historic buildings had to be rebuilt. Traditional techniques of lightweight vault construction were used and the possibilities of new techniques were incorporated. Even some systems were patented. This article deals with the construction of light vaults between the mid-19th and mid-20th centuries in Belgium, one of the pioneering countries in the industrial revolution.