The barrel-vault, groined (or four-part vault), and dome vaults were the three types of vaults employed. The barrel-vault was by far the most common type, used for churches, monasteries, and cathedrals from the 11th century until the 15th century. It was made out of timber, with thick walls and a flat ceiling covered with barrels or trusses held up by wooden pillars. The groined vault was used mainly in large halls and open spaces where the barrel vault would not fit. It was also used as an upper floor over a series of chambers or rooms with barrel vaults. Finally, the dome vault was used for more modern buildings after 1220. It had the highest roof profile of all vaults, which allowed more light into the space. Barrel vaults were easy to build and inexpensive. They were also very strong because there were no supporting beams under the vaulted ceiling; instead, it was supported only by wall ties and columns. This left the barrel vault well suited for larger structures like churches and monasteries that required greater load-bearing capacity but did not need to be particularly delicate or refined in appearance. Although they were widely used during the Romanesque period, barrel vaults began to give way to groined vaults around 1100.