Double layer barrel vaults are a group of ‘lattice space structures’ that are widely used to cover large areas. These areas have been also used by public as shelters after earthquakes. So, it is necessary to ensure the safety of these structures against earthquakes. Unfortunately, the available research results on the behaviour of barrel vaults are rather scarce and there is no universally accepted code of practice for assessing the earthquake loading for these structures. In this work, the linear and nonlinear behaviour of a family of barrel vaults are investigated under horizontal and vertical components of earthquakes. A significant volume of interesting results is obtained as an outcome of this study. It is shown that both horizontal and vertical components of earthquakes may cause some elements of the vaults to buckle and this may lead to collapse. It is therefore essential that barrel vaults are properly designed for earthquakes. In the current work, some formulae are suggested for assessing the horizontal and vertical effects of earthquakes on barrel vaults. The formulae will ease the task of designing these structures.