In this study, integrated photovoltaic thermal roofing system has been successfully built and tested to improve the photovoltaic efficiency as well as providing domestic hot water supply. The major components of the solar photovoltaic thermal (PV/T) collector in this study comprise of amorphous silicon solar cells arranged in series that were adhered to the roofing structure. Unified structure of copper tube absorbers with oscillatory flow configuration was attached to the back plate which was insulated with glass wool from the surrounding. The entire PV/T collector has been mounted on a manual two degree solar tracker that can be adjusted toward the exposure of maximum solar irradiation. The effect of altering parameters such as water mass flow rate and irradiance on the collector's efficiencies has been carried out. The combined efficiency including photovoltaic and thermal efficiencies varies from 70.53% to 81.5% in the PV/T system with the oscillatory flow configuration. The present study has shown better results in terms of PV/T efficiency in comparison with the prior corresponding experiments.