Prefabricated Floor Panels for Houses

Prefabricated floor panels for houses were commonly used in early 20th-century construction as floor slabs, belonging to engineered modules or panels that are produced in prefabrication yards and transported to the site for installation. The manufacturing process involves first nailing wooden planks to create a hollow mold, placing steel reinforcement within the mold, and then pouring concrete. After drying, the wooden planks are knocked out to form the prefabricated panel. Depending on structural differences, prefabricated panels are divided into solid and hollow types, with the hollow structure achieving lightweighting by reducing non-load-bearing concrete, lowering material costs, and facilitating transportation and installation.

Prefabricated panels have a wide range of applications but also significant limitations. They were initially used in residential buildings, highway ditch covers, and roof insulation layers, among other scenarios. Residential buildings constructed in China before 1985 commonly adopted prefabricated panel structures. However, their drawbacks have gradually become apparent:

1. Insufficient seismic performance: The rigid connection between prefabricated panels and walls makes them prone to structural damage or even complete collapse during earthquakes due to incompatible deformation.
2. Poor sound insulation and thermal insulation: The hollow structure or thin-wall design leads to rapid sound transmission and heat loss, requiring additional soundproof cotton or insulation layers.
3. Difficulty in internal structural adjustments: As fixed modules, prefabricated panels make it challenging to modify walls or add pipelines during later renovations, limiting spatial flexibility.
4. High risk of water leakage: Cracks can easily form at panel joints due to material shrinkage or construction defects, leading to prominent rainwater leakage issues after long-term use.
5. Short service life: The design life is typically 30 to 50 years, much shorter than the over 70 years for cast-in-place concrete structures, with a significant decline in load-bearing capacity after aging.

Policy and industry trends: Repair-oriented, with demolition subject to specific conditions. With advancements in construction technology, cast-in-place concrete and prefabricated buildings have gradually replaced prefabricated panel houses. Since 2022, China has implemented renovation policies focusing on repairing and upgrading prefabricated panel houses, with demolition only for buildings identified as dangerous by professional institutions or included in urban redevelopment plans. Dangerous building identification must meet standards for structural safety and durability, and demolition compensation is only provided for eligible buildings. Therefore, not all prefabricated panel buildings will be demolished; their retention depends on building condition and urban planning needs.