How to Renovate Prefabricated Panel Houses

The renovation of prefabricated panel houses should combine structural safety assessments with functional requirements, achieving safety upgrades and functional optimizations through technical means. The specific methods are as follows:

I. Structural Renovation Techniques

1. Wall-to-Beam Conversion: Suitable for structural upgrades of three-story prefabricated panel houses, this technique involves removing load-bearing walls and replacing them with a beam-column framework system, enabling the building to be extended to seven stories. The renovation requires the construction of a temporary support system (such as full scaffolding) before gradually removing the walls and installing steel or concrete beams to ensure continuous load transfer paths.
2. Structural Reinforcement and Inspection: Prior to renovation, a professional agency should be commissioned to conduct a structural safety assessment, focusing on inspecting the width of cracks in the prefabricated panels (requiring grout injection or carbon fiber sheet reinforcement for cracks exceeding 0.3 mm), the rust rate of bolts (requiring replacement with high-strength bolts if exceeding 30%), and the connection status of ring beams. During construction, steel pipe supports should be installed every 1.2 meters along the length of the prefabricated panels, and key nodes should use H-shaped steel beam underpinning (with a cross-section of at least 200*200 mm) to ensure construction safety.

II. Local Repair and Enhancement

1. Panel Joint Repair: After removing the original joint filler, No. 6 deformed steel bars (spaced 200 mm apart) should be implanted and C30 fine aggregate concrete should be poured to enhance the crack resistance of the panel joints.
2. Constructional Column Addition: Constructional columns measuring 240*240 mm should be added at the four corners of the house, using No. 6 and No. 8 steel bars for reinforcement and reliably connecting them to the floor slab to improve overall seismic performance.
3. Exterior Wall Treatment: After removal, the exterior walls should undergo plastering and steel bar implantation and grouting treatment, with the implantation depth not less than 15d (steel bar diameter) and the grouting material having a strength grade of at least M30 to enhance the load-bearing capacity of the exterior walls.

III. Functional Upgrades and Renovations

1. Sound Insulation Optimization: Adding 50 mm thick sound insulation boards to the walls and replacing windows with double-glazed units (with a gap of at least 12 mm) can reduce noise by 30-40 decibels.
2. Waterproofing Treatment: For roof leaks, the original waterproofing layer should be removed, a 50 mm thick C30 concrete roof should be poured, and SBS modified asphalt waterproofing membrane (with a thickness of at least 4 mm) should be laid, with a slope of not less than 2% for drainage.
3. Space Optimization: Demolition work should be carried out in sections (not exceeding 30% of the total floor area per day), using symmetrical construction to avoid eccentric loads and prohibiting the use of heavy hammer impacts for demolition to prevent foundation settlement.

IV. Professional Assessment and Customized Solutions

Before renovation, a structural safety report should be issued by a detection agency certified by the Ministry of Housing and Urban-Rural Development, and a plan should be formulated based on data such as crack severity (active cracks requiring dynamic monitoring) and steel bar rust rate (electrochemical rust removal followed by epoxy coating application). Data shows that approximately 60% of old prefabricated panel buildings can extend their service life through grout injection, steel plate reinforcement, or pile foundation reinforcement without requiring complete demolition and reconstruction.