Prefabricated Panels for Flat Roofs

The use of prefabricated panels for flat roofs is relatively common in rural self-built houses, but they have significant advantages and disadvantages that require careful consideration based on actual circumstances.

I. Advantages of Prefabricated Panel Roofs

1. Low Cost: Prefabricated panels are relatively inexpensive. For example, for a 40-50 square meter roof, the total cost is approximately 800 yuan, and sellers usually handle the hoisting, saving on labor costs.
2. Convenient Construction: Prefabricated panels are produced in a standardized manner in factories, allowing for fast on-site installation, which is suitable for self-built house projects with tight schedules or limited budgets.

II. Core Defects of Prefabricated Panel Roofs

1. Poor Waterproof Performance:
   • High risk of leakage, with 8 out of 10 houses experiencing rain leakage issues, and waterproofing construction is difficult to completely resolve. Due to the gaps at the joints of prefabricated panels, waterproofing effects can only be verified after the rainy season, potentially increasing later maintenance costs.
2. Weak Thermal Insulation:
   • The thermal insulation effect of 12-centimeter-thick hollow prefabricated panels is limited. In summer, the indoor temperature is significantly higher than the outdoor temperature, while in winter, the insulation is insufficient, requiring additional covering with materials such as cinder and lime to compensate, increasing construction complexity.
3. Insufficient Earthquake Resistance:
   • Prefabricated panels have a spliced structure with poor integrity and are not suitable for earthquake-prone areas. During earthquakes, they are prone to roof collapse due to breakage at the joints, posing safety hazards.

III. Other Limitations

1. Short Service Life: The overall lifespan of a prefabricated panel house is about 30-50 years, which is shorter than that of a cast-in-place concrete structure, and long-term maintenance costs are higher.
2. Poor Sound Insulation: The hollow structure has weak sound insulation capabilities, allowing raindrop sounds or external noise to easily enter the room on rainy days.

IV. Alternative Solution Recommendations
If the budget allows, a cast-in-place concrete roof is a better choice:

• Strong Integrity: No joints, providing more reliable waterproofing performance and a durability of over 50 years.
• Optimized Thermal Insulation: Performance can be enhanced by adding insulation layers or using a double-layer structure.
• Cost Comparison: For a 40-50 square meter cast-in-place roof, the cost is approximately 3000 yuan or more. Although higher than that of prefabricated panels, long-term maintenance costs are lower.

Summary: Prefabricated panel roofs are suitable for scenarios with extremely low budgets, non-earthquake-prone areas, and low requirements for living comfort. However, their defects in waterproofing, thermal insulation, and earthquake resistance must be accepted. In modern construction, cast-in-place concrete or prefabricated buildings have gradually replaced prefabricated panels, becoming safer and more durable choices.