Renovation of Old Houses with Prefabricated Slabs

The renovation of old houses with prefabricated slabs requires a combination of structural safety assessments and functional upgrades, achieving renovation goals through scientific construction and the application of new technologies. The specific methods are as follows:

1. Understanding the Situation: Professional Inspection and Targeted Repairs

First, entrust a qualified inspection agency to conduct a comprehensive 'check-up' of the house, focusing on issues such as wall cracks, steel reinforcement corrosion, and foundation settlement. Develop a repair plan based on the inspection results:

• Wall Cracks: Cracks less than 0.3 millimeters wide can be repaired with grout injection; if the cracks penetrate the wall or are wider than 0.3 millimeters, steel plate reinforcement or steel bar grouting is required.
• Roof Leaks: Remove the original waterproof layer, lay new waterproof membranes or apply waterproof coatings, and ensure proper roof drainage slope.
• Unstable Foundation: If uneven foundation settlement occurs, use pile driving reinforcement or grout lifting techniques to restore foundation bearing capacity.

2. Functional Upgrades: Enhancing Living Comfort

For issues such as poor sound insulation and low space utilization in old houses, renovations can be carried out in the following ways:

• Sound Insulation Optimization: Fill sound insulation cotton inside the walls and install sound insulation boards on the outer layer; replace windows with double-glazed units to reduce noise transmission by 70%.
• Space Reorganization: Remove non-load-bearing walls (subject to structural assessment confirmation) to optimize indoor layout; use light steel keel partitions to divide functional areas and reduce space wastage.

3. Structural Reinforcement: Ensuring Construction Safety and Long-Term Stability

Structural reinforcement is the core of renovation and must strictly follow these steps:

1. Pre-Demolition Assessment: Focus on inspecting the width of cracks in prefabricated slabs (special treatment required for cracks wider than 0.3 millimeters) and the connection status with ring beams (bolts with a corrosion rate exceeding 30% need replacement).
2. Temporary Support: Install steel pipe supports every 1.2 meters along the length of the prefabricated slabs, use H-section steel beams for critical node underpinning, with beam sections not less than 200×200 millimeters.
3. Slab Joint Treatment: Remove the original filling material, implant No. 6 threaded steel bars, and pour C30 fine aggregate concrete; add 240×240 millimeter constructional columns at the corners of the house, connected with floor slab reinforcement.
4. Demolition Principles: Adopt a segmented demolition method of 'middle first, then sides', with daily demolition not exceeding 30% of the total floor area; monitor stress changes in the support system in real-time and prohibit demolition by heavy hammer impact.

4. Adopting New Technologies: Modularization and Digitalization for Efficiency

It is recommended to apply the CSCEC First Bureau's E-MIC Prefabricated Concrete Box House System, which pre-positions pipeline layouts, unit combinations, and other aspects in the factory through digital design, achieving standardized production. Its advantages include:

• Short Construction Period: On-site work reduced by 60%, with project duration shortened by more than 30%;
• High Environmental Protection: Construction waste reduced by 80%, meeting green renovation requirements;
• Strong Flexibility: Modules can be freely combined to adapt to different unit requirements, suitable for scenarios such as old residential area renovations.

By following these steps, structural safety hazards and functional defects in old houses with prefabricated slabs can be systematically addressed, achieving a safe, comfortable, and efficient upgrade of the living environment.