Masonry barrel vaults are widespread in the built heritage of the Mediterranean area. Post earthquake observations have highlighted their vulnerability under seismic loads especially when they are used as secondary elements carrying their own weight only. This study explores the effectiveness of seismic risk reduction for calcarenite masonry barrel vaults using Glass Fiber Reinforced Polymer (GRFP) cementitious reinforced mortar (CRM) in the extrados. Half-scale masonry vault specimens with and without retrofitting have been constructed and subjected to non-symmetrical vertical loading until failure. Structural performances are assessed in terms of resistance and displacements. Digital Image Correlation (DIC) was also employed to track damage initiation and propagation. A detailed Finite Element (FE) model was developed using OpenSees/STKO and calibrated with the experimental tests. A real case study of a calcarenite masonry barrel vault has been numerically analyzed using multiple stripe analysis to derive fragility curves. The results will show a quantification of the vulnerability reduction achieved under different boundary conditions and reinforcement percentage.