The House Roof is Made of Prefabricated Panels

The use of prefabricated panels for house roofs offers the advantages of low cost and fast construction, but it also presents issues in terms of waterproofing, earthquake resistance, thermal insulation, joint sealing, and the overall structure has defects such as weak earthquake resistance, poor sound and thermal insulation, and a limited service life.

Advantages

The most notable advantage of prefabricated panel roofs is their low cost and rapid construction speed. They are manufactured in factories and hoisted into place on-site, allowing single-story roof hoisting operations to be completed in a day or half a day, significantly shortening the construction period. This makes them particularly suitable for projects that are sensitive to cost or have tight deadlines.

Disadvantages

1. Poor Waterproof Performance
   Waterproofing prefabricated panel roofs is challenging, with a significantly higher probability of leaks compared to other structural forms. According to statistics, approximately 80% of houses with prefabricated panel roofs in rural areas experience leakage issues, and achieving long-term complete sealing of the waterproof layer is difficult, necessitating frequent maintenance.

2. Weak Earthquake Resistance
   Prefabricated panels are assembled structures with poor overall integrity and a low earthquake resistance coefficient. In earthquake-prone areas, the connection nodes are prone to damage, significantly increasing the risk of roof collapse. Therefore, they are not suitable for high-intensity earthquake zones.

3. Insufficient Thermal Insulation
   The thickness of prefabricated panel floors is typically around 12 centimeters. Although they are hollow structures, their thermal insulation effect is limited. In summer, indoor temperatures are easily affected by external heat, and in winter, heat is lost quickly, requiring secondary installation of thermal insulation materials (such as foam boards or ceramsite concrete) to improve performance.

4. Joint Vulnerabilities
   The joints between two prefabricated panels are structural weak points. Affected by temperature changes, foundation settlement, and other factors, cracks are prone to form at the joints, leading to issues such as water seepage and air leakage, and even affecting structural safety.

Overall Structural Defects

Prefabricated panel houses originated in the early 20th century, and many residential buildings constructed in China before 1985 adopted this structure. With the development of construction technology, their defects have become increasingly apparent:

• Limited Service Life: The design life of existing prefabricated panel houses is approximately 30-50 years, after which structural performance deteriorates rapidly.
• Poor Sound and Thermal Insulation: Hollow floors have weak sound and temperature insulation capabilities, resulting in low living comfort.
• Renovation Limitations: Since 2022, China has implemented renovation policies focusing on repairing and reinforcing prefabricated panel houses, with only those identified as dangerous buildings being demolished. Overall renovation is challenging.