Renovation of Prefabricated Slab Houses

When renovating prefabricated slab houses, it is essential to focus on structural safety, load control, construction standards, and functional upgrades. The key points are as follows:

1. Structural Safety Assessment

Before renovation, a professional agency must be commissioned to conduct a comprehensive inspection of the house, focusing on issues such as wall cracks, steel bar corrosion, and foundation settlement. For example, approximately 60% of prefabricated slab buildings from the 1990s can be reinforced (e.g., with carbon fiber reinforcement or additional structural columns) rather than demolished and rebuilt, saving costs and extending the building's lifespan. If cracks are found at the joints of prefabricated slabs or the floor slab sags, construction must be halted immediately, and a reinforcement plan must be developed.

2. Load Control and Material Selection

• Load Limits: The live load limit for prefabricated slab floors is typically 2.0 kN/㎡, and the load from the finishing layer (e.g., tiles or flooring) should be controlled within 0.5 kN/㎡. If underfloor heating is required, ultra-thin materials should be selected to reduce the load.
• Material Selection: The use of heavy materials such as marble and granite is strictly prohibited. Lightweight building materials such as light steel keels, gypsum boards, and aluminum ceiling panels are preferred. For example, integrated aluminum ceiling panels can be used for bathroom ceilings, providing both waterproofing and reduced load on the floor slab.

3. Water and Electricity Renovation Standards

• Wiring Restrictions: Horizontal grooving in prefabricated slabs is prohibited as it may damage the steel bars inside the slabs, leading to fractures. Lighting wires should be routed along the base of walls or from the floor, while socket wiring should be routed vertically with a groove depth not exceeding 3 cm.
• Pipeline Routing: Specialized design should be carried out in combination with structural load limits to avoid concentrated piping at the joints of prefabricated slabs. For example, water pipes are recommended to be routed along the ceiling for easier maintenance and reduced impact on the floor slab.

4. Wall Renovation Restrictions

• Non-Load-Bearing Wall Removal: Only non-load-bearing walls are allowed to be removed, and confirmation must be obtained through detection with professional instruments (e.g., steel bar scanners). Manual chiseling should be used for removal, and the use of large machinery such as impact drills is prohibited to prevent vibration damage to the prefabricated slabs.
• Load-Bearing Wall to Beam Conversion: If a load-bearing wall needs to be removed, professional teams must carry out the construction. For example, in a case in Hubei, temporary supports were added, replaced with steel beams, and the bottom wall was removed only after ensuring structural stability for 15-20 days.

5. Functional Upgrade Solutions

• Soundproofing: Install soundproofing mats between walls and floor slabs and replace windows with double-glazed units to improve sound insulation by 70%.
• Waterproofing and Leak Prevention: The roof should be relaid with SBS waterproofing membrane, and the bathroom floor should be coated with two layers of waterproofing paint and equipped with a water barrier, with the wall base extending upwards by more than 30 cm.

6. Construction Preparation and Protection

• Preliminary Preparation: Complete detailed drawing深化 (deepening of drawings), load calculation, and material testing (e.g., radioactivity of stones and formaldehyde emission from boards).
• Finished Product Protection: Protect entry doors, windows, and floors with protective film, set up dust reduction equipment during demolition, and promptly transport waste to designated locations.

Case Reference: A two-story prefabricated slab house in Hubei was transformed into a workshop on the first floor by converting walls to beams, fully opening up the space; a prefabricated slab building from the 1990s saw significantly improved sound insulation and waterproofing performance after partial reinforcement, with costs only half of those for demolition and reconstruction.