Architectural principles and the aesthetic appearance of historic buildings are relatively coherent in certain time periods according to the dominant architectural style, construction techniques according to the location of the building, and knowledge of the craftsman. More than this, when discussing vernacular architecture, the materials used are usually obtained from nearby locations, leading to the adaptation of the considered structural system while maintaining the appearance of the building. Considering this, a study was conducted on a series of historic churches from Gorj County, built at the end of the 19th and beginning of the 20th century, which present two different approaches. The study was performed on churches that suffered slight damages after the series of seismic events in the region in 2023. The analysis showed they all have a similar shape and were built using stacked river stone foundations and brick masonry walls with lime-based mortar. Above the main nave, most of the churches presented a brick masonry vault, but in some peculiar cases, the brick vault was replaced with a timber one decorated similarly to the brick one. Above the vault, the roof structure is made of timber in both cases. After the seismic events, the experts involved in the diagnosis process performed extensive numerical analysis of their behaviour, obtaining information about their structural behaviour. Based on the results, four churches were chosen in the region, and their structural behaviour was analysed, highlighting the influence of the used timber vault on seismic behaviour compared with the behaviour of typical brick vault historic churches of the same region.