Renovation of Walls in Prefabricated Panel Houses

The renovation of walls in prefabricated panel houses should focus on structural reinforcement, combined with waterproofing and moisture-proofing techniques, selecting professional teams and standardizing contract management, while adjusting construction details according to regional climates.

I. Structural Safety and Substrate Treatment

1. Joint Reinforcement
The joints between prefabricated panels are key hidden points for water seepage and structural loosening. Epoxy resin grouting should be used to repair the gaps, and steel beams or carbon fiber sheets should be installed for reinforcement (e.g., in the case of a 30-year-old rural house, steel beam supports can enhance overall stability). Before construction, the moisture content of the wall, hollow areas, and hidden cracks should be tested. In the Xi'an market, local repair, partial wall removal, or full wall removal plans are required based on the degree of damage to avoid cracking after renovation due to loose substrates.

2. Substrate Defect Repair
Remove the original plaster layer down to the substrate. For issues such as sanding and honeycomb cracks, use waterproof mortar for leveling. In the renovation of old houses in Fuzhou, after exposing the red brick base, the flatness error should be treated to ensure a solid substrate; in a case in the Putuo District of Shanghai, for loose sanding on the roof of a prefabricated panel house,精细化 (fine) repair techniques were adopted to provide a firm attachment base for the waterproof layer.

II. Key Measures for Waterproofing and Moisture Proofing

1. Wall Waterproofing
In damp areas (such as bathrooms and kitchens), waterproof mortar leveling should be done first, followed by the application of waterproof coatings to prevent moisture penetration, which can lead to efflorescence and mildew. Due to the concentrated damp return period during the rainy season in Xi'an, the contract should clearly specify 'closed procedures', including wall consolidation rolling, mesh installation, and other moisture-proof steps to avoid additional items later.

2. Coordinated Roof Waterproofing
If the roof is of a prefabricated panel structure, it should be renovated simultaneously. In a Shanghai case, rigid filling and reinforcement of panel joints and national standard membrane waterproofing across the entire area were adopted to prevent roof leakage from causing wall dampness, forming a 'roof-wall' dual waterproofing system.

III. Construction Standards and Contract Specifications

1. Transparent Inspection and Quotation
Reject 'all-inclusive lump-sum pricing'. The construction party should conduct on-site inspections and provide tiered quotations based on the degree of damage. Market data in Xi'an shows that 64.7% of homeowners encounter passive additional items, with an average overspend of 17.5%. Therefore, the contract should clearly define the budget range and conditions for additional items.

2. Closed-Loop Process Management
The contract should list 17 full processes (such as putty application, primer and topcoat painting, finished product protection, etc.) and state that 'the final settlement price shall not exceed 3% of the budget' to eliminate vague expressions. A Shanghai case provides a 5-year written warranty to ensure traceable responsibility.

3. In-House Team and Process Standards
Choose a team with a fixed plastering crew (with an average work experience of ≥8 years) to avoid inconsistent process standards due to subcontracting. In the renovation of old rural houses, priority should be given to addressing structural safety (such as reinforcing load-bearing walls with carbon fiber sheets) before considering functional upgrades.

IV. Regional Adaptability Adjustments

• Special Climate in Xi'an: With a winter-summer temperature difference of nearly 50°C and dryness during the heating season, enhanced substrate anti-cracking treatment (such as mesh installation and the use of elastic putty) is required to reduce the risk of cracking due to thermal expansion and contraction.
• Old Rural Houses: The renovation cost is approximately 800-1200 yuan/㎡. Priority should be given to addressing structural safety, followed by functional upgrades such as water and electricity renovations.