How to Distinguish Prefabricated Panel Houses

There are several ways to distinguish prefabricated panel houses:

Examine the construction year: Generally, houses built more than 15 years ago mostly use prefabricated panel structures, while those built in the last 15 years are more likely to use cast-in-place slabs. In the early days, due to limitations in technology and construction efficiency, prefabricated panels were widely used because of their ease of installation and lower cost. In recent years, with advancements in building technology, cast-in-place concrete structures have gradually become the mainstream choice for new houses due to their superior integrity and earthquake resistance.

Observe the areas where pipes are laid: Inside the house, if you see columns or pre-drilled holes, these are typically features of prefabricated panel structures. This is because prefabricated panels are manufactured with pre-set channels for pipes and wiring, whereas cast-in-place slabs are poured on-site in one piece and do not require such pre-drilled holes.

Inspect the interior walls of the house: Walls in prefabricated panel houses usually do not have beams, and there are no columns where walls intersect. This is because prefabricated panels are laid independently and do not require additional support structures. Conversely, if there are beams above the walls and columns where walls intersect, it is likely a cast-in-place slab structure.

Observe the floor slab structure: Prefabricated panels typically appear as regular blocks with noticeable gaps between them. In contrast, cast-in-place slabs are smooth without visible joints, indicating better integrity. Prefabricated panels are usually rectangular with clear, regular joint lines.

Drill holes in the floor slab: This is a relatively direct but cautious method. Prefabricated panels are usually manufactured with holes at regular intervals to reduce weight and facilitate installation. If you use a hammer drill to make three holes about 5 centimeters apart on the floor slab, and if you hit an empty space while drilling, it indicates a prefabricated panel. However, this method may damage the floor slab, so it is not recommended unless absolutely necessary.

Tap the floor slab and listen to the sound: Gently tap the floor slab with a hard object. If the sound is clear and has a long echo, it may be a prefabricated panel; if the sound is dull, it may be a cast-in-place slab. This is because prefabricated panels have internal cavities that cause sound to echo, whereas cast-in-place slabs have better integrity, resulting in a duller sound.

Check the house design drawings: If you have the design drawings of the house, you can directly check the type of floor slab structure. The design drawings usually clearly indicate whether the floor slab is a prefabricated panel or a cast-in-place slab, which is the most direct and accurate method of determination.