Thickness of Prefabricated Floor Slabs for Houses

The common thicknesses of prefabricated floor slabs for houses are 120mm and 150mm, while the thickness of solid pre-stressed concrete floor slabs for composite slabs is 50mm (it can be 40mm when the span is less than 3600mm). The following is a detailed explanation:

Thickness of Conventional Prefabricated Slabs
In house construction, when ordinary prefabricated slabs are used as floor slabs or roof slabs, the common thickness specifications are 120mm and 150mm. These two thicknesses can meet the load-bearing requirements of general residential buildings, office buildings, and other civil buildings, while also taking into account economic efficiency and construction convenience. A thickness of 120mm is suitable for areas with relatively small loads and short spans, such as bedrooms and living rooms in ordinary houses; a thickness of 150mm is mostly used in spaces with larger loads or longer spans, such as corridors in public buildings and shopping mall business areas. The selection of thickness should be comprehensively determined based on building functions, structural calculations, and code requirements.

Thickness of Pre-stressed Concrete Floor Slabs for Composite Slabs
Composite slabs are composed of prefabricated floor slabs and cast-in-place concrete layers. The prefabricated floor slabs use pre-stressing technology to improve crack resistance. According to the code, the standard thickness of solid floor slabs is 50mm, which is suitable for most conventional span scenarios. When the span is less than 3600mm, the floor slab thickness can be optimized to 40mm to reduce material consumption and lower the structural dead weight. It should be noted that thickness adjustments should be strictly based on parameters such as span and load for structural verification to ensure that they meet the requirements for load-bearing capacity, deformation, and crack control.

Core Bases for Thickness Selection

1. Structural Safety: The thickness should meet the requirements for flexural resistance, shear resistance, and stiffness through calculations to avoid structural damage or excessive deformation due to insufficient thickness.
2. Construction Feasibility: An excessively small thickness may affect the production, transportation, and installation efficiency of prefabricated slabs, while an excessively large thickness increases material costs and structural dead weight.
3. Economic Efficiency: On the premise of meeting safety and functional requirements, standardized thicknesses should be preferred to reduce costs.

In actual projects, the thickness of prefabricated slabs should be comprehensively determined by structural designers based on building types, usage functions, load conditions, and construction techniques, and strictly comply with relevant standards such as the "Code for Design of Concrete Structures" (GB50010).