Lighting Wiring for Prefabricated Slab Houses

The following methods can be referred to for the lighting wiring layout in prefabricated slab houses, and it is essential to strictly adhere to safety regulations to avoid damaging the floor slab structure:

1. Wiring Through Ceiling Space

In areas with suspended ceilings, wires can be routed through the internal ceiling space. Pay attention to the following key points:

• Fixing Requirements: Wire conduits must be securely fixed using dedicated clips or brackets to prevent loosening, which could lead to wire wear or poor contact.
• Insulation Performance: Wires must use flame-retardant insulating materials that comply with national standards, and the total cross-sectional area of wires inside the conduit should not exceed 40% of the conduit's diameter to prevent overheating and potential safety hazards.
• Maintenance Accessibility: Access panels should be reserved in the ceiling for easy future maintenance or wiring modifications.

2. Wall Grooving for Wiring

If wiring needs to be installed in walls, the following standards must be followed:

• Structural Protection: Before grooving, confirm the wall type. It is strictly prohibited to damage load-bearing walls or the connections between prefabricated floor slabs and walls. For non-load-bearing walls, the grooving depth should not exceed one-third of the wall thickness, and the width should not exceed 1.5 times the outer diameter of the wire conduit.
• Groove Treatment: After grooving, fill the grooves with cement mortar, ensuring the surface flatness error does not exceed 3mm, and apply anti-crack putty to repair the wall surface.
• Conduit Fixing: Wire conduits should be fixed with clips every 50cm, and curved sections should use conduit benders to create arc-shaped bends, avoiding sharp bends that could damage the wires.

3. Wiring Through Prefabricated Slab Holes

When installing heavy fixtures like chandeliers, wiring can be routed through pre-reserved holes in the prefabricated slabs:

• Drilling Position: Avoid the steel reinforcement within the prefabricated slabs. Use a professional water drill for hole making, with a diameter not exceeding 50mm.
• Wire Protection: Wires passing through the holes should be threaded through metal flexible conduits or PVC flame-retardant conduits, secured at both ends with locknuts to prevent the wires from being cut by the hole edges.
• Load Consideration: If the chandelier weighs more than 3kg, expansion bolts or chemical anchors should be pre-embedded in the floor slab, and an independent suspension rod should be added for reinforcement.

4. Flexible Wiring Technique (Special for Prefabricated Slabs)

For the hollow structure of prefabricated slabs, a flexible wiring technique can be adopted for easier future maintenance:

• Conduit Insertion: Insert a flexible conduit (with elasticity) into the holes of the prefabricated slab, ensuring the bending angle is greater than 90°. Leave 4-5cm of slack before trimming the excess.
• Fixing Method: Thread the conduit into the internal cavity of the prefabricated slab, apply special adhesive to one end and screw it into a matching connector, and fix the other end to the wall with edge clips to form a detachable flexible wiring system.
• Safety Notice: Ensure the conduit is free from damage and the connectors are well-sealed to prevent pests or moisture from entering.

Prohibited Actions: Since prefabricated floor slabs have a hollow structure, it is strictly prohibited to groove the slab surface for concealed wiring, as this could compromise the slab's integrity, leading to reduced load-bearing capacity or even collapse risks. All wiring modifications must comply with the requirements of the "Residential Decoration and Renovation Engineering Construction Specifications" (GB 50327-2001), and it is recommended to be carried out by professional electricians.