How to Identify Prefabricated Panel Houses

Identifying prefabricated panel houses can be done through the following methods:

1. Observe the Floor Structure Prefabricated panels typically exhibit a regular block-like structure, with noticeable gaps between panels, especially at the edges or corners of the floor. In contrast, cast-in-place floors are poured as a whole, resulting in a smooth, flat surface without obvious seams, offering greater structural integrity.

2. Check the Construction Year Prefabricated panel structures were commonly used in early buildings. Houses built more than 15 years ago (especially before 2003) are mostly prefabricated panel structures. After 2003, the state banned the use of prefabricated panels in newly built commercial housing, and since then, newly constructed commercial housing has primarily used cast-in-place floors. However, note that exceptions may still exist for some self-built houses or non-commercial housing.

3. Tap the Floor to Listen for Sounds Gently tap the floor with a hard object (such as a key or small hammer):

• Prefabricated Panel: Produces a clear, resonant sound with a long echo, and the vibration travels in a single direction (along the length of the panel).
• Cast-in-Place Floor: Emits a dull sound, with vibrations spreading in all directions without a clear directionality. This method should be combined with other characteristics for comprehensive judgment to avoid misidentification.

4. Examine the House Design Drawings If the original design drawings of the house can be obtained, directly check the annotations for the floor structure type. Drawings that clearly indicate “prefabricated panel” or “assembled floor” refer to prefabricated panel houses, while “cast-in-place floor” or “reinforced concrete integral floor” indicate a cast-in-place structure.

5. Observe the Appearance Characteristics of the Floor

• Crack Patterns: Cracks on the ceiling of prefabricated panels often appear as parallel straight lines (similar to marks made by a ruler), while cracks on cast-in-place floors are irregular and scattered.
• Hole Markings: During the manufacturing of prefabricated panels, round holes with a diameter of about 8 centimeters are usually reserved (for wiring or weight reduction). If such regular holes are visible on the floor surface, it can be identified as a prefabricated panel.
• Wall Structure: Houses with prefabricated panels often lack beam and column support in the walls (especially in brick-concrete structures), while houses with cast-in-place floors usually have obvious beam and column frameworks.

6. Observe the Areas Where Pipes are Laid In houses with prefabricated panels, holes need to be reserved or pipe seams avoided during pipe installation, so regular perforations or seams can be seen around the pipes. Cast-in-place floors, on the other hand, can have pipes directly slotted and buried, resulting in a tighter integration between the pipes and the floor without obvious reserved holes.

7. Drill Holes in the Floor for Verification (Proceed with Caution) Inside prefabricated panels, reserved holes with a diameter of about 8 centimeters are spaced approximately every 30 centimeters. Use an impact drill to make three holes 5 centimeters apart on the floor. If holes are encountered, it indicates a prefabricated panel. This method may damage the floor structure and is only recommended for cautious operation in non-load-bearing areas, with priority given to other non-destructive methods.