The House Structure is a Prefabricated Panel Structure

When the house structure is a prefabricated panel structure, it is a building constructed primarily with prefabricated panels. These panels are cement components prefabricated in factories, formed by nailing wooden models, arranging steel bars, and pouring cement. They come in two types: solid and hollow.

Basic Characteristics of Prefabricated Panel Structures

Prefabricated panels are cement components prefabricated in factories. During production, wooden models are first nailed, steel bars are arranged inside, and cement is poured. After forming, the molds are removed for use. Depending on their internal structure, prefabricated panels are divided into solid and hollow types. The hollow structure achieves lightweighting by reducing the amount of concrete in non-load-bearing parts, lowering material costs and减轻楼板自重 (reducing the self-weight of the floor slab). However, its load-bearing capacity is relatively weaker than that of solid panels.

History and Current Status of Prefabricated Panel Structures

Prefabricated panel structures were widely used in early 20th-century construction due to their fast construction speed, low cost, and suitability for large-scale industrial production. However, as building technology advanced, their limitations gradually became apparent: prefabricated panels are connected by splicing, resulting in poor overall integrity and weak seismic performance; over time, cracks easily form at the splices, affecting structural safety. Therefore, after 2003, the state prohibited the use of prefabricated panel structures in newly built commercial housing, instead promoting modern building systems such as frame structures and reinforced concrete structures to enhance the safety and durability of houses. Currently, prefabricated panel structures mainly exist in older buildings, especially residential properties built before 2003.

Identification Methods for Prefabricated Panel Structures

1. Construction Era Assessment: Older houses (especially those built before 2003) are mostly prefabricated panel structures, while newly built commercial housing rarely adopts them.
2. Physical Feature Observation:
   • Ceiling: Parallel cracks often appear on the ceilings of prefabricated panel structures, a common phenomenon at the splices.
   • Knocking Sound: Knock on the wall with a hard object. If the sound is clear and the vibration propagates unidirectionally (e.g., only horizontally), it may be a prefabricated panel structure; if the sound is dull and the vibration spreads in all directions, it may be a reinforced concrete structure.
   • Floor Slab Holes: Hollow prefabricated panel floor slabs may have circular holes with a diameter of about 8 centimeters, used to reduce weight or lay pipelines.
3. Wall Structure Analysis: If the house lacks obvious beam-column support, with walls directly bearing the load, and no obvious exposed steel bars at the connection between the floor slab and walls, it may be a prefabricated panel structure.

Limitations of Prefabricated Panel Structures

Prefabricated panel structures have poor overall integrity due to their splicing method, resulting in weak seismic performance and susceptibility to collapse during earthquakes. Additionally, their durability is low, and they are prone to cracking and water leakage over time, leading to high maintenance costs. Therefore, modern construction has phased out prefabricated panel structures in favor of safer and more durable building systems.