Plumbing and Electrical Renovation of Prefabricated Floor Slab Houses

When renovating the plumbing and electrical systems of prefabricated floor slab houses, it is crucial to pay special attention to the standard operations of circuit and waterway renovations to ensure safety and avoid structural damage.

Key Points for Circuit Renovation

1. Prohibition of Horizontal Slotting
   Prefabricated floor slabs are prefabricated components, and horizontal slotting can compromise their structural integrity, leading to the risk of slab fractures and endangering all rooms above. Vertical slotting or bypass methods must be adopted:

   • Prioritize slotting along the base of walls and threading wires through newly drilled holes;
   • If the floor allows, wires can be directly routed through the floor (with attention to waterproofing);
   • Houses with suspended ceilings can utilize the ceiling space for wiring, eliminating the need for slotting and pipe embedding.

2. Special Issues in Old Houses
   Old prefabricated slab buildings in areas like Xi'an commonly suffer from aged original circuits, such as aluminum-core wires, lack of grounding, and no equipotential bonding in kitchens and bathrooms. During renovation, the wiring must be completely replaced, and grounding wires and equipotential terminal boxes must be added to ensure electrical safety. The cost of renovating old houses is 20%—30% higher than that of new houses, primarily due to increased costs for demolition, debris removal, and re-routing of plumbing and electrical systems.

Key Points for Waterway Renovation

1. Standardized Pipe Layout

   • Orientation: Cold and hot water pipes should be laid horizontally and vertically to avoid cross interference;
   • Slope: The slope of the pipes must comply with regulations to ensure smooth drainage;
   • Fixing: Pipe clamps should be spaced reasonably to prevent pipe shaking or deformation.

2. Installation of Outlets and Valves

   • Cold and hot water outlets must be level, following the principle of "hot on the left, cold on the right";
   • Various valves (such as main valves and branch valves) should be installed flat and straight for easy operation and maintenance;
   • The main water inlet valve should be placed in an easily accessible indoor location, and the water pipes and fittings should be checked for damage, sand holes, or cracks before installation.

3. Reservation for Special Equipment
   If equipment such as water dispensers or water purifiers needs to be installed in the kitchen, reserve water inlet and outlet connections and power supply positions in advance to avoid rework later.

4. Slotting and Insulation Requirements

   • Both cold and hot water pipes must be embedded in the wall, with the slotting depth complying with the pipe diameter requirements;
   • Cold and hot water pipes must not be slotted in the same groove to prevent heat conduction from affecting usage;
   • In northern regions, it is recommended to insulate hot water pipes to reduce heat loss.

Other Considerations

• Water Meter Location: The water meter should be installed in a position that is easy to read and not obstructed, with an appropriate distance from the wall for easy maintenance later;
• Waterway Issues in Old Houses: If the original water pipes are severely aged (such as rusted cast iron pipes), they should be completely replaced with new materials like PPR pipes to ensure water quality safety.