Renovation of Old Prefabricated Panel Houses

The renovation of old prefabricated panel houses should be systematically carried out from four aspects: structural reinforcement, construction sequence, thorough investigation, and functional upgrading, as detailed below:

1. Structural Reinforcement: Ensuring Safety is the Core

• Comprehensive Inspection and Assessment: Before renovation, a professional agency should be commissioned to conduct a structural safety assessment of the house, focusing on checking the width of cracks in the prefabricated panels (special treatment is required for cracks exceeding 0.3 millimeters), the connection status between the prefabricated panels and the ring beams (bolts with a rust rate exceeding 30% need to be replaced), as well as whether the foundation is sinking and whether there are cracks in the walls. Based on the inspection results, a reinforcement plan should be formulated. For example, grouting repair can be used for minor wall cracks, while steel plate reinforcement is required for severe cracks.
• Erecting Temporary Support Systems: Set up steel pipe supports every 1.2 meters along the length of the prefabricated panels. For key nodes, use H-shaped steel beams with a cross-section of no less than 200*200 millimeters for underpinning to ensure structural stability during demolition or reinforcement.
• Reinforcing Panel Joints and Walls: Remove the original filling material from the panel joints, implant No. 6 deformed steel bars, and pour C30 fine aggregate concrete. Add 240*240 millimeter constructional columns at the four corners of the house, tie them with No. 6 and No. 8 steel bars, and connect them to the floor slab to enhance the overall tensile resistance. After the exterior walls are demolished, they should be repainted and reinforced with steel bar implantation and grouting to increase the load-bearing capacity.

2. Construction Sequence: Following Scientific Demolition Principles

• Segmented and Symmetrical Demolition: Adopt the principle of 'middle first, then sides', with a daily demolition volume not exceeding 30% of the total floor area, maintaining symmetry to avoid structural displacement.
• Real-time Monitoring of Support Systems: During demolition, monitor the stress changes in the support systems. Violent demolition methods such as heavy hammer impacts are prohibited to prevent shock damage to the foundation.

3. Thorough Investigation: Accurately Diagnosing the Root Causes of Problems

• Professional 'Full-body Check-up': Commission a qualified inspection agency to use professional instruments to comprehensively inspect issues such as wall cracks, steel bar corrosion, and foundation settlement. For example, if the roof is leaking, a new waterproof layer needs to be laid; if the foundation is unstable, pile driving reinforcement is required.

4. Functional Upgrading: Enhancing Living Comfort

• Sound Insulation Optimization: Install sound insulation panels and replace windows with double-glazed ones, which can improve sound insulation by about 70%.
• Thermal Insulation Improvement: For the poor thermal insulation of prefabricated panel houses, measures such as exterior wall insulation layers and roof insulation panels can be adopted (specific methods need to be customized according to the house structure).
• Humanized Space Renovation: Adjust the internal layout according to needs, such as optimizing the ventilation and lighting in the kitchen and bathroom or adding storage space.