Is the Roof of a Commercial House Made of Prefabricated Panels?

Whether the roof of a commercial house is made of prefabricated panels can be determined by the construction year, physical characteristics, wall structure, and floor markings. Existing prefabricated panel houses have issues such as weak earthquake resistance, which can be improved through renovation.

Determination Methods

• Construction Year: Houses built before 2003 generally use prefabricated panels, as the state banned the use of prefabricated panels in newly built commercial houses after 2003. Therefore, commercial houses built after 2003 mostly use cast-in-place panels, while older houses are mostly prefabricated panel structures.
• Physical Characteristics: The ceiling of prefabricated panels will have parallel cracks, while the cracks in cast-in-place panels are irregular. When knocking on the wall, prefabricated panels will emit a 'ding ding' sound, and the vibration will be conducted in one direction, while the vibration of cast-in-place panels will spread in all directions.
• Wall Structure: Houses without beams and columns are mostly prefabricated panel structures, while those with beams and columns are cast-in-place structures.
• Floor Markings: If there is a circular hole with a diameter of 8 centimeters on the floor, it can be determined as a prefabricated panel.

Existing Issues

Existing prefabricated panel houses generally have some defects. Weak Earthquake Resistance: In the event of natural disasters such as earthquakes, the structural stability of prefabricated panel houses is poor, making them susceptible to damage and posing a threat to the safety of occupants. Poor Sound Insulation and Heat Insulation: The material and structural characteristics of prefabricated panels result in poor sound insulation and heat insulation performance, affecting the comfort of living. Limited Service Life: The service life of prefabricated panel houses is approximately 30-50 years. Over time, various aging problems may occur in the houses.

Renovation Measures

According to the '15th Five-Year Plan for Urban Renewal' issued by the State Council, more than 500,000 non-complete housing units, including C and D-grade dangerous housing and prefabricated panel houses in cities, will be renovated, and the renovation of prefabricated panel houses and earthquake resistance reinforcement in earthquake-prone areas will be steadily promoted. For prefabricated panel houses identified as Class A or B with no major issues in the main structure, living conditions can be improved through the renovation of old residential areas, such as repairing roof leaks, replacing aging pipelines, and installing elevators.