Unreinforced masonry (URM) walls at a decommissioned building in St. Louis, Missouri were tested to failure. The walls belonging to the present experimental program were subjected to out-of-plane loading. Previous work on URM and reinforced masonry walls strengthened with FRP laminates has shown remarkable increases in capacity and ductility. However, most of this research has been conducted under laboratory conditions, where, many times, it is a difficult task to represent real field conditions. In this context, this experimental program offered a singular opportunity for performing field experimentation on URM walls strengthened with Glass, Aramid and Carbon Fiber Reinforced Polymers (GFRP, AFRP and CFRP, respectively), as well as Glass Near Surface Mounted Rods. Parameters such as the type of composite system, strip width, and FRP installation methods were evaluated. A mechanism of failure caused by a shear-compression effect lead to the fracture of either the upper or lower boundary masonry units. Due to this failure mode, the walls were not able to develop a higher capacity compared to the control specimen.