Prefabricated Panels for Industrial Factory Building Roofs

Prefabricated panels for industrial factory building roofs were a common roof structural form in early 20th-century architecture, typically used as floor slabs or insulation layers. However, they had drawbacks such as poor waterproofing performance and susceptibility to cracking, and have gradually been replaced by cast-in-place concrete and prefabricated buildings.

Structure and Manufacturing Process

Prefabricated panels for industrial factory building roofs are formed by nailing wooden models, arranging steel bars, and pouring cement. They come in two types: solid and hollow. The hollow structure achieves lightweighting by reducing non-load-bearing concrete, meeting load-bearing requirements while reducing material consumption. This standardized manufacturing process made them widely used in early industrial buildings, especially suitable for large-scale repetitive construction scenarios.

Performance Defects and Issues

1. Inadequate Waterproofing Performance: Joints exist at the splicing points of prefabricated panels, which are prone to forming cracks due to long-term rainwater erosion and physical damage, making roof leakage a common problem. Even if materials such as asphalt are used for repair, it is difficult to completely eliminate leakage risks.
2. Poor Structural Stability: During installation, they are simply spliced together, with a lack of effective connections at the joints. If the foundation is not properly treated or the building settles unevenly, it can easily lead to crack propagation or even severe cracking, threatening structural safety.
3. Limited Durability: Concrete materials are prone to surface spalling under long-term weathering and freeze-thaw cycles, increasing the risk of steel bar corrosion and further reducing structural lifespan.

Modern Alternative Solutions

1. Cast-in-Place Concrete: By forming a seamless structure through integral pouring, it completely eliminates leakage risks and can flexibly adjust the shape and reinforcement according to design requirements, enhancing overall structural integrity.
2. Prefabricated Buildings: Using modular factory-prefabricated components, such as CMC composite modular buildings that employ steel-concrete integral pouring technology, significantly improve seismic performance. The construction period is 30% shorter than traditional methods, and the components have higher precision and more stable quality.

Policy Orientation and Renovation Directions

Since 2022, China has implemented a policy of renovating old buildings, focusing on repairing and renovating prefabricated panel houses, primarily addressing roof leakage and reinforcing structural cracks, while improving insulation and fire resistance. Only buildings that meet the criteria for dangerous structures are demolished to avoid resource waste caused by large-scale reconstruction. This policy not only preserves the historical value of the buildings but also meets modern usage requirements through technological upgrades.