How to Identify Prefabricated Panel Houses
There are several methods to identify prefabricated panel houses:
Observe the Floor Structure
Prefabricated panels typically appear as regular blocks with noticeable gaps between them. This is because they are pre-made in factories and then transported to construction sites for assembly. In contrast, cast-in-place floors are formed by pouring concrete directly on-site, resulting in a smooth, seamless surface. By carefully examining the floor surface, if you can see distinct block patterns and gaps, the house is likely to have prefabricated panels.
Check the Construction Year
Houses built earlier often used prefabricated panel structures. After 2003, the use of prefabricated panels in newly constructed commercial housing was prohibited in China. Generally, houses built more than 15 years ago are likely to have prefabricated panel structures, while those built within the last 15 years are more likely to have cast-in-place floors. However, this is only a rough reference, and other methods should be used for comprehensive judgment.
Tap the Floor and Listen to the Sound
Gently tap the floor with a hard object. If the sound is clear and has a long echo, it may indicate a prefabricated panel. This is because prefabricated panels have internal cavities that cause sound to reflect and resonate, producing a clear and long-lasting echo. In contrast, cast-in-place floors are solid concrete structures, and sound energy dissipates quickly during propagation, resulting in a relatively dull sound when tapped.
Examine the House's Design Drawings
If you have access to the house's design drawings, you can directly check the type of floor structure. The drawings will clearly indicate whether the floor is made of prefabricated panels or cast-in-place concrete, providing the most direct and accurate method of identification.
Observe the Floor Appearance
The ceiling of a prefabricated panel house may have parallel cracks that appear to be measured with a ruler, resulting from the assembly and stress during the use of the panels. In contrast, cracks in cast-in-place floors are irregular and lack obvious patterns. By observing the crack patterns on the ceiling, you can make a preliminary judgment about the house's structural type.
Examine the Wall Structure
Houses without prominent beams and columns are likely to have prefabricated panel structures. The load-bearing structure of prefabricated panel houses is relatively simple, relying mainly on the walls for support, so there are usually no obvious beams and columns on the walls. In contrast, houses with beams and columns are more likely to have cast-in-place floors, which are poured together with the beams and columns to form an integrated load-bearing system.
Look at the Pipe Installation Areas
The presence of columns or pre-drilled holes is a characteristic of prefabricated panel houses. During manufacturing, prefabricated panels can be made with holes as needed to facilitate later pipe installation. In contrast, cast-in-place floors require on-site drilling according to the pipe locations and generally do not have pre-set columns or holes.
Drill Holes in the Floor
Prefabricated panels are typically made with holes about 8 cm in diameter every 3 cm during manufacturing. Use an impact drill to make three holes about 5 cm apart on the floor. If you hit an empty space while drilling, it indicates a prefabricated panel. However, this method can cause damage to the floor and is not recommended for use without certainty.
