The paper collects the results of an innovative experimental campaign carried out on full-scale, non-structural masonry barrel vaults, so to assess, by means of quasi-static cyclic tests, the lateral performances of a strengthening technique based on the application, at the extrados or the intrados, of a 30mm thick mortar layer with Glass Fiber-Reinforced Polymer meshes embedded. The samples were made of solid bricks, with a radius of 2060mm and are 770mm wide and 120mm thick; three vaults have a span of 3980mm and other three of 3575 mm. It emerged that the presence of the composite mesh contrasted the collapse mechanism, leading to resistance increases ranging from 2 to 4 times that of plain masonry and increasing considerably the ultimate horizontal displacements at crown section. A simplified analytical approach is also presented in the paper, to quantify the samples lateral resistance for assigned geometry and mechanical characteristics of materials.