Prefabricated Panels for Eaves of Self-Built House Roofs

It is feasible to use prefabricated panels for the eaves of self-built house roofs, but scientific and rigorous control over design, production, installation, and inspection is required.

Feasibility Conditions for Prefabricated Panel Eaves

The feasibility of using prefabricated panels for eaves primarily depends on the design plan and the load-bearing capacity of the panels. During the design phase, the specifications of the prefabricated panels should be determined based on the structural type of the building (such as brick-concrete or frame) and the dimensions of the eaves (such as the overhang length and width). If the eaves are large (e.g., with an overhang exceeding 60 centimeters), the prefabricated panels need to be strengthened (e.g., by increasing the reinforcement ratio of steel bars) and improved in water resistance (e.g., by using waterproof concrete or applying waterproof coatings). At the same time, structural calculations should be conducted to ensure that they can withstand environmental forces such as wind loads, snow loads, and construction-related additional loads.

Advantages of Prefabricated Panel Eaves

1. Efficiency and Cost Advantages: Prefabricated panels can be produced in a standardized manner in factories, with a production cycle that is more than 50% shorter than on-site pouring. Moreover, mold control ensures dimensional accuracy and reduces manual errors. Installation adopts a lifting process, with a construction speed more than three times faster than traditional wooden formwork setup, and the overall cost can be reduced by 20%-30%.
2. Quality and Environmental Protection: Factory production allows for strict control over key parameters such as concrete mix ratios and curing conditions, with a product strength compliance rate of over 98%. On-site work is reduced by 60%, significantly lowering the generation of construction waste (such as formwork scraps and concrete residues) and dust pollution.
3. Maintenance Convenience: The surface of the prefabricated panels is polished, with a smoothness of Ra ≤ 3.2μm, making it less prone to dust accumulation. Their durability is 2-3 times that of traditional wooden eaves, and the maintenance cycle can be extended to 10 years under normal use.

Precautions for Prefabricated Panel Eaves

1. Design Rationality: Finite element analysis should be used to verify the load-bearing capacity of the connection nodes between the prefabricated panels and the main structure to ensure compliance with the requirements of the "Building Structural Load Code." The eaves design should avoid complex curves to reduce the difficulty of prefabricated panel processing.
2. Construction Precision: During installation, special fixtures should be used to fix the prefabricated panels, with an error controlled within ±2mm. The joints should be filled with high-strength mortar or structural adhesive, and an additional layer of waterproof membrane should be provided.
3. Quality Inspection: After construction, a water spraying test (lasting more than 2 hours) should be conducted to verify the waterproof performance, and an infrared thermal imager should be used to detect any hollow areas.
4. Safety Protection: For high-altitude work, double-row scaffolding should be erected, and safety equipment such as safety harnesses and fall arresters should be provided. Construction personnel must hold relevant certificates.

Disadvantages of Using Prefabricated Panels for the Entire Roof

Prefabricated panels are not integrally poured with the main structure, making them prone to detachment due to weak connections during earthquakes. Their coefficient of linear expansion differs from that of the concrete main structure, which may lead to cracks when the temperature difference exceeds 25°C. In rural self-built houses, the leakage rate at the joints of prefabricated panels due to uneven foundation settlement can be as high as 40%, and their thermal insulation performance is 15%-20% lower than that of cast-in-place panels.