Prefabricated House Plumbing and Electrical Renovation

The renovation of plumbing and electrical systems in prefabricated houses requires standardized operations in four aspects: electrical circuits, water pipelines, special considerations for old houses, and construction processes, to ensure safety and functional suitability.

Core Points of Electrical Circuit Renovation

1. Avoid Horizontal Trenching: Horizontal trenching on prefabricated floor slabs is strictly prohibited as it can easily lead to slab fractures, threatening the structural safety of the upper floors. Three alternative solutions are recommended:
   • Vertical Trenching Along Wall Edges: Trench vertically along the edge of the wall and lead wires to the target location through newly opened holes;
   • Floor Wiring: If there is no interference from backfill leveling layers on the floor, pipelines can be laid directly;
   • Utilizing Ceiling Space: If the house has a ceiling design, pipelines can be hidden within the ceiling without trenching.
2. Material and Specification Requirements: Strong and weak electrical wires should be laid separately in different pipes with appropriate spacing. The ratio of wire diameter to pipe diameter should not exceed 40%. Arc-shaped treatments should be used at corners to ensure flexible wire handling. Old houses should have aging wires replaced and be designed with separate circuits for different functions (e.g., independent circuits for lighting, sockets, and air conditioning) to prevent overloading.

Key Measures for Water Pipeline Renovation

1. Pipe Material Upgrade: Replace original rusty iron pipes with PPR pipes and follow the principle of 'running along the ceiling rather than the floor' for easy future maintenance. The spacing between cold and hot water pipes should be maintained at more than 15 centimeters to prevent pipe deformation due to thermal expansion and contraction.
2. Drainage System Optimization: Redesign the distribution structure of cast-iron drainage pipes. When connecting to PVC downpipes, ensure proper anti-seepage treatment (e.g., using sealing rings or hot-melt connections).
3. Pressure Test: After completion, conduct a water pressure test of over 0.6 MPa for 30 minutes without leakage for acceptance.

Special Considerations for Old Houses

1. Structural Protection: For prefabricated houses built before the 1990s, floor trenching may damage the decorative layer or even the floor slab structure of the lower floors. It is recommended to remove old floors and lay exposed pipes, securing them with pipe clamps.
2. Valve Replacement: If the original water supply control valve does not close tightly, it should be replaced with a reliable valve (e.g., a ball valve) to avoid the risk of water leakage later.
3. Scientific Power Distribution Design: Allocate the power distribution system according to the electrical appliance configuration requirements. For example, high-power areas such as kitchens and bathrooms should have separate circuits to prevent overloading.

Standardized Construction Process

1. Plan Formulation: Design a plumbing and electrical layout diagram based on the house structure and requirements;
2. Material Inspection: Check whether pipes, wires, etc., meet national standards;
3. Removal of Old Pipelines: Carefully remove the original plumbing and electrical lines to avoid damaging the structure;
4. Wiring and Pipe Laying: Lay new pipelines according to specifications, and wrap strong and weak electrical crossings with tin foil to prevent interference;
5. Equipment Installation: Connect terminal devices such as switches, sockets, and faucets;
6. Inspection and Testing: Conduct electrical power-on tests and water pipeline pressure tests;
7. Enclosure and Restoration: Restore the original condition of walls and floors;
8. Acceptance and Delivery: Check the pipeline layout diagram to ensure no omissions or problems.

Safety Tips: The renovation process should be carried out by professionals, strictly adhering to building codes and using qualified materials to avoid safety hazards caused by non-compliant construction.