First Floor of Prefabricated Panel Building

The safety, moisture-proofing, and structural characteristics of the first floor of a prefabricated panel building need to be evaluated based on multiple factors. Here is a detailed analysis:

Safety Assurance

• Quality and Responsibility: Construction units are responsible for inspecting building materials such as prefabricated panels. Uninspected or non-compliant materials must not be used, as they may pose safety risks to the building. If a building collapses due to quality defects, causing damage, the construction and development units shall be jointly liable unless they can prove the absence of such defects.
• Key Points for Hidden Danger Inspection:
  • Structural Integrity: Check for uniform settlement of the foundation, tilting of the building, and the firmness of connections between prefabricated panels and load-bearing walls. Insufficient support length or loose node connections of prefabricated panels on walls may lead to structural issues.
  • Condition of Components: Pay special attention to whether there are horizontal through-cracks, deflection deformations, or end damage at the bottom of prefabricated panels. Be vigilant if vertical or diagonal cracks appear in load-bearing walls, or if the lintel above door and window openings cracks.
  • Usage and Modification: Unauthorized removal or modification of load-bearing walls, illegal additions, or changes in use can significantly increase the building's load, causing the prefabricated panels to become overloaded and potentially leading to safety accidents.

Moisture-Proofing Measures

In rural self-built houses, a prefabricated panel suspended floor can be constructed on the ground beam for foundation moisture-proofing. The principle is to "exchange space for dryness" by leaving a 30 - 50 cm cavity between the foundation and the first-floor ground. Underground moisture rises into the cavity and dissipates, preventing it from reaching the first-floor ground and thus ensuring dryness.

Structural Characteristics and Recommendations

• Overall Structural Stability: If the first floor of a house is a prefabricated panel frame structure, and the second and third floors are cast-in-place structures, the overall structural stability depends on the rational design and construction quality of the frame structure. If the design is reasonable and the construction quality meets standards, the safety of the house can be ensured.
• Performance Differences: Prefabricated panels are standardized in production and offer fast construction speeds, but their connections may have weak points that affect the overall structural stiffness and seismic performance. Cast-in-place slabs have better integrity, stiffness, and seismic performance, as well as superior waterproofing and noise reduction properties. However, their construction period is longer, and costs are slightly higher.
• Recommendations: During construction, consult a professional structural engineer to supervise and evaluate the overall structural design and construction quality. Take appropriate reinforcement measures for potential structural weak points, such as the connections between prefabricated and cast-in-place slabs, to improve the overall structural stiffness and seismic performance.