How to Identify Prefabricated Panel Houses

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

1. Check the construction year Prefabricated panel structures were commonly used in early buildings. Houses built more than 15 years ago are more likely to use prefabricated panels, while those built after 15 years generally adopt cast-in-place concrete structures. This difference stems from the evolution of construction technology—prefabricated panels were widely used in early residential construction due to their high construction efficiency and low cost; cast-in-place panels, with their strong integrity and good seismic performance, have gradually become the mainstream choice.

2. Observe the characteristics of the floor slab structure Prefabricated panels are composed of prefabricated concrete blocks joined together, presenting a regular block structure on the surface. The gaps between the panels are relatively obvious, and there may be height differences or cracks at the joints. Cast-in-place panels, on the other hand, are formed into a whole by pouring concrete on-site, with a flat and smooth surface and no joint marks. If regular block boundaries are found on the floor slab, it can be preliminarily judged as a prefabricated panel structure.

3. Inspect the pipeline layout and hole design Prefabricated panel houses usually have reserved pipeline holes or column support structures in the floor slab. For example, regularly arranged reserved holes can be seen in areas such as bathrooms and kitchens. Cast-in-place panels complete pipeline embedding through one-time pouring without the need for additional holes. In addition, prefabricated panels have holes with a diameter of about 8 centimeters reserved every 3 centimeters during production. A test can be conducted by using an impact drill to make three holes at 5-centimeter intervals on the floor slab. If the drill goes into an empty space, it indicates a prefabricated panel.

4. Analyze the relationship between walls and beams and columns In prefabricated panel houses, the walls usually bear the load directly. There are no beam and column supports at the intersections of walls, and there is no horizontal beam structure above the walls. Cast-in-place panel houses, however, disperse the load through a beam and column system. Obvious columns can be seen at the intersections of walls, and there are continuous horizontal beams above the walls. If the internal walls of a house exist independently without beam and column connections, caution should be exercised regarding a prefabricated panel structure.

5. Tap the floor slab to identify the material by sound Gently tap the floor slab with a hard object (such as a screwdriver). Due to the internal hollow space or existing holes in prefabricated panels, they will emit a clear and long-echoing 'drum sound'. Cast-in-place panels, with their dense concrete, produce a dull and short sound. This method should be combined with other characteristics for comprehensive judgment to avoid misjudgment due to differences in floor slab thickness.

6. Consult the original design drawings If the house retains the original design drawings, the floor slab structure type can be directly checked in the drawings. Drawings that clearly mark 'prefabricated panel' or 'cast-in-place panel' can serve as the most authoritative basis for judgment. This method is suitable for structural verification before second-hand house transactions or house renovations.