In the past years, considerable progress has been made toward the salvage and restoration of the valuable monuments of Historic Cairo. One of these monuments is the Qala’un Complex situated in the center of Fatimids Cairo and considered one of the most important Islamic monuments. Due to increase of the population and economic activities around the building and severe environmental attack, the whole monument showed deterioration in some walls, facades, columns and arches. The wooden roof over the central qibla iwan of the mosque particularly showed architectural and structural deterioration. Whereby comprehensive material investigation and structural analysis were carried out in order to outline the causes of the problem and suggest the proper conservation and rehabilitation schemes needed to restore this valuable historical monument. In this study, an innovative strengthening technique is presented using fiber-reinforced polymer (FRP) laminates bonded to the wooden beams, together with another traditional method by using steel beams. Both strengthening techniques are discussed and found to provide structural efficiency together with simplicity, low disturbance, minimum intervention, and reversibility particularly important in restoration of monuments and architectural heritage buildings.