Repair of Prefabricated Panels on Old House Roofs

There are two main methods for repairing prefabricated panels on old house roofs: waterproof renovation and overall reinforcement.

Waterproof Renovation

Prefabricated panel roofs are prone to issues such as deformation, cracking of panel joints, frequent hidden water leakage, and poor weather resistance of gutters. These problems can lead to roof leaks, affecting the normal use and living comfort of the house. To address these issues, a systematic waterproof renovation plan can be adopted.

• Specific Steps: First, conduct a full-scale roof clearance to remove debris and dust from the roof surface, providing a good foundation for subsequent construction. Next, perform fine repairs on the base layer to address issues such as cracks and hollowing. Then, carry out rigid filling and reinforcement of the panel joints to enhance their sealing and stability. After that, use national standard thickened waterproof membranes for full-scale protection to effectively prevent water penetration. Finally, for gutters, use a dedicated exposed waterproof reinforcement system for renovation to improve their weather resistance and waterproof performance.
• Case Reference: The prefabricated panel roof waterproof renovation project in Phase I of Zhonghuan Jiayuan in Putuo District abandoned the traditional symptomatic treatment methods of local joint repair and surface glue application. Instead, it used national standard genuine waterproof materials from Oriental Yuhong throughout the project, with standardized and meticulous implementation of each step. After the project was completed and passed the acceptance inspection, a 5-year formal written warranty was provided to the homeowners, fully demonstrating the effectiveness and reliability of this waterproof renovation plan.

Overall Reinforcement

• Pouring a Reinforced Concrete 'Composite Layer': First, clean the floating dust on the surface of the prefabricated panels to ensure good adhesion between the concrete and the panels. Then, lay a steel mesh with a diameter of 6 millimeters, with a spacing of 20 centimeters square. The steel mesh serves as a reinforcing element. Next, pour fine aggregate concrete with a grade not lower than C25, with a typical thickness of 5 to 8 centimeters. Through the reinforcing effect of the steel mesh and the adhesion of the concrete, the originally independent prefabricated panels are 'welded' into a whole, thereby enhancing the overall stiffness of the roof.
• Using 'I'-Beams as Crossbeams: Determine the placement density according to the size of the selected profile. Taking 20-sized steel as an example, place three beams (forming a '+' shape with the panels). Erect 'I'-beam columns at both ends for support, with the columns fixed to the walls. This can enhance the hardness of the prefabricated panels and improve the load-bearing capacity of the roof.
• '+' Beam Reinforcement: Add a layer of concrete on the prefabricated panels, remove one prefabricated panel in the middle to create a crossbeam, add a vertical beam ('+' beam) on the crossbeam, and then add another floor slab to increase the thickness of the floor slab, making the beams and floor slab a whole. However, it should be noted that for this reinforcement method, the walls still need to be reinforced to ensure the stability of the entire structure.