House Prefabricated Slab Renovation Methods

The renovation of house prefabricated slabs should be systematically carried out from multiple aspects such as structural safety and functional optimization. The specific methods are as follows:

1. Structural Safety Assessment
Before renovation, a professional agency should be commissioned to conduct a comprehensive inspection, focusing on checking the crack width of the prefabricated slabs (if exceeding 0.3 millimeters, epoxy resin grouting or carbon fiber reinforcement should be used) and the connection status with the ring beams (if the bolt corrosion rate exceeds 30%, they should be replaced with stainless steel bolts). At the same time, check whether the floor bearing capacity meets the current code requirements. If there is severe aging or deformation, a special reinforcement plan should be formulated.

2. Roof Renovation
After removing the original wooden roof, the building height should be maintained unchanged, and a new concrete roof should be poured. The construction points include:

• Use C30 commercial concrete with a thickness of not less than 120 millimeters
• Set up a two-way Φ8@200 steel bar mesh to enhance the overall integrity
• Control the roof slope within 2%-3% to ensure smooth drainage
• After completion, conduct a 48-hour water storage test to verify the waterproofing effect

3. Exterior Wall Treatment
After removing the original finish layer, implement a three-step treatment:

• Base layer cleaning: Remove the hollow parts to the solid base layer
• Reinforcement with planted rebars: Plant Φ6 rebars every 300 millimeters vertically, with a depth of not less than 100 millimeters
• Grouting treatment: Use high-strength non-shrink grouting material to fill the gaps, with a strength grade of not less than M30

4. Support System Construction
During the construction phase, a dual protection system should be established:

• Temporary support: Set up Φ48*3.5 steel pipe supports every 1.2 meters along the length of the prefabricated slabs, with a pole spacing of not more than 1.0 meters
• Permanent reinforcement: Use h200*200 steel beams for underpinning at key nodes, and conduct shear calculations at the connections with the original structure

5. Slab Joint Treatment
Implement refined treatment for the detected cracks:

• For cracks with a width of 0.3-1.0 millimeters: Open a V-shaped groove and then grout with epoxy mortar
• For cracks with a width greater than 1.0 millimeter: Plant a two-way Φ6@200 steel bar mesh and pour C30 fine aggregate concrete
• The curing period should be not less than 14 days, during which no load should be applied

6. Addition of Structural Columns
Add structural columns at key positions such as the four corners of the house and stairwells:

• Cross-sectional dimensions: 240*240 millimeters
• Reinforcement: 6Φ12 longitudinal rebars + Φ6@200 stirrups
• Set up a stepped joint at the connection with the floor and pour high-strength concrete

7. Construction Sequence Control
Strictly implement the principle of "segmental demolition and symmetrical construction":

• The area demolished in a single day should not exceed 30% of the total floor area
• Use water drilling for cutting instead of impact demolition
• Monitor the stress changes of the support system in real-time (the warning value is set at 80% of the design value)

8. Functional Upgrades

• Sound insulation optimization: Add 50-millimeter-thick sound insulation cotton to the walls and use 6+12A+6 insulated glass for the windows
• Aging-friendly renovation: Add handrails in the stairwells and make anti-slip treatments in the bathrooms
• Intelligent upgrades: Pre-bury pipelines to create conditions for the subsequent installation of smart home systems

After the renovation is completed, settlement observations should be carried out for not less than 3 months to ensure structural safety and stability. All renovation plans must be reviewed and approved by a drawing review agency before implementation.