Renovation of Prefabricated Slab Houses

Renovation of prefabricated slab houses requires a focus on structural characteristics and hidden dangers, aiming to enhance safety and living experience through systematic renovation, though it comes with high costs and requires adherence to specific principles.

I. Core Issues and Hidden Dangers

Prefabricated slab houses, due to limitations in construction techniques, generally face the following problems:

1. Structural Weaknesses: Weak overall integrity, with slab joints prone to cracking, leading to roof leakage. Dynamic deformation accelerates the failure of waterproof layers. With a designed lifespan of about 40 years, there is a high risk of base-layer diseases such as wall cracks and hollowing.
2. Functional Aging: Water and electrical lines are often made of aluminum or lack grounding, showing severe aging. The house layout is unreasonable (e.g., dark bathrooms, kitchens without windows), resulting in poor lighting and ventilation.
3. Hidden Risks: Complex base-layer diseases may cause water seepage issues. Improper removal or modification of non-load-bearing walls can easily undermine structural stability.

II. Key Renovation Measures

1. Systematic Roof Waterproofing Renovation

   • Base Treatment: Repair cracks and hollowing to ensure a flat and solid base.
   • Slab Joint Treatment: Use rigid filling materials to seal gaps, preventing secondary cracking due to dynamic deformation.
   • Comprehensive Waterproofing: Lay national-standard waterproof membranes across the entire roof area, avoiding the “band-aid” approach of local repairs.

2. Complete Reorganization of Water and Electrical Lines

   • Replace Aging Lines: Eliminate aluminum lines, adopt copper lines, and add grounding to meet modern safety standards.
   • Standardized Construction: Implement circuit branching control to prevent overloading. Replace water pipes with durable materials like PPR to reduce leakage risks.

3. Wall Reinforcement and Base Repair

   • Crack Treatment: Use grouting or mesh plastering techniques based on crack width to prevent expansion.
   • Hollowing Repair: Remove hollowing areas, re-plaster, and reinforce with mesh to enhance adhesion.

4. Space Optimization and Layout Adjustment

   • Remove Non-Load-Bearing Walls: Improve lighting and ventilation, but confirm wall properties to avoid damaging load-bearing structures.
   • Adhere to the “No Ground Modification” Principle: Ground renovation in prefabricated slab houses can easily trigger structural issues. It is recommended to retain the original ground or cover it with lightweight materials.

III. Costs and Policy Support

• Cost Characteristics: Renovation costs are 20%-30% higher than those for new home decoration, mainly due to the high investment in demolition, removal, and concealed works (e.g., water and electricity, waterproofing).
• Policy Benefits: In 2026, Xi'an will reduce renovation costs through measures such as home appliance subsidies and smart home subsidies. Stay tuned for local policy updates.

IV. Precautions

• Prioritize resolving structural safety hazards (e.g., waterproofing, water and electricity) before considering functional and aesthetic upgrades.
• Choose qualified construction teams to avoid rework due to craftsmanship defects.
• Regularly inspect renovation results, especially roof waterproofing and water and electrical lines, to extend the house's service life.