The strengthening of the reinforced concrete (RC) elements enhances their strength, stiffness, ductility, and durability. This study examined the efficiency of the Side-Near-Surface-Mounted (SNSM) technique over the Near-Surface-Mounted (NSM) technique for RC beams. Utilized Glass Fiber Reinforced Polymer (GFRP) composite as a strengthening reinforcement for flexural strengthening. The conventional mortar served as a potential epoxy substitute, while the epoxy glue served as a gluing mediator between the concrete substance and GFRP composite. Five medium-sized beam specimens were used, one of which served as a reference. Two of the beam samples were strengthened employing the SNSM method, and the remaining two were strengthened engaging the NSM method, using GFRP composite rebars and the preferential portions of epoxy adhesive and regular mortar, respectively. The experiments were carried out under four-point flexural loading in a monotonic condition. The applied loads and displacement of the beams were recorded over the course of the experiments in a TDS-530 data logger, and the cracks and mechanisms of failure were visible to the unaided eye. The experimental outcomes exhibited that, in comparison to the reference specimen, SNSM and NSM strengthening procedures vastly enhanced the flexural load-bearing capacity and toughness. In terms of flexural load-bearing capabilities, failure modes, toughness, and ductility performance, the SNSM strengthening technique exceeded the NSM technique. The SNSM-strengthened specimens failed owing to flexure, whereas the NSM-strengthened samples collapsed in brittle manner because of premature debonding. Depending on the findings, the SNSM technique might be a more affordable and effective option than the existing NSM technique for the construction industry.