The Floor Slab of the House is a Prefabricated Panel

The use of prefabricated panels for house floor slabs was mainly seen in early 20th-century buildings. After 2003, the state prohibited the use of prefabricated panels in newly built commercial housing, and most old houses have prefabricated panel structures. The following provides a detailed introduction to the definition, characteristics, and identification methods of prefabricated panel floor slabs:

Definition of Prefabricated Panel Floor Slabs

Prefabricated panel floor slabs are concrete prefabricated components produced and processed in a prefabrication yard and directly transported to the construction site for installation.

Characteristics of Prefabricated Panel Floor Slabs

• Dimensions and Specifications: The maximum span of residential prefabricated panels is 4.2 meters (without considering modular dimensions; customization is required for spans exceeding this). The widths are mostly 500mm and 600mm, with common thicknesses of 120mm and 150mm. In terms of live load capacity, Grade I panels for general residential use can withstand a live load of 1kN/m², while Grade II panels can withstand a live load of 2kN/m².
• Advantages: Construction is convenient, significantly shortening the construction period; costs are relatively low, saving on construction expenses; construction efficiency is high, facilitating faster project progress; quality is stable, as production in the prefabrication yard is less affected by external environmental factors; and it is environmentally friendly and energy-saving, reducing dust and noise pollution from on-site construction.
• Disadvantages: There are issues with gaps, as joints between different prefabricated panels are prone to gaps, affecting aesthetics and waterproofing performance; high dimensional accuracy is required, as significant dimensional deviations can affect installation quality and overall structural stability; sound insulation is limited, as sound travels relatively easily between prefabricated panels; and seismic performance and overall integrity are poor, as prefabricated panels are prone to relative displacement under external forces such as earthquakes, leading to structural damage.

Methods for Identifying Whether a House Floor Slab is a Prefabricated Panel

• Check the Construction Year: Old houses generally use prefabricated panel structures, while most newly built commercial housing after 2003 uses cast-in-place slabs.
• Observe Physical Characteristics: Prefabricated panel ceilings have parallel cracks; when tapping the floor slab, the sound is crisp and ringing, and the vibration only propagates in one direction; there are circular holes about 8 centimeters in diameter on the floor slab.
• Examine the Wall Structure: Houses with no beams or columns in their wall structures are mostly likely to have prefabricated panel floor slabs.