Wiring in Prefabricated Slab Houses

When laying wires in prefabricated slab houses, it is essential to strictly adhere to the principle of protecting the structural integrity of the prefabricated slabs and select a safe and compliant construction plan based on the spatial characteristics, as detailed below:

I. Prioritize Wiring in Ceiling Spaces

If the house has a ceiling structure, wire conduits can be installed within the ceiling. This method utilizes the concealed space of the ceiling to accommodate the wiring, without the need to damage the prefabricated floor slabs, while ensuring that the wires are securely fixed and have good insulation properties. During construction, note the following:

1. Use flame-retardant PVC wire conduits to prevent deformation due to high temperatures;
2. Secure the wire conduits with conduit clamps, with a spacing of no more than 1 meter to prevent loosening;
3. Seal the conduit openings with sealant after threading to prevent the entry of pests and rodents.

II. Avoid Key Structures When Cutting Grooves in Walls

When cutting grooves in walls for wiring, strictly adhere to the following rules:

1. Avoid load-bearing walls and connections to prefabricated slabs: Load-bearing walls are the core of the house's structure. Damaging the connections between prefabricated slabs and walls can lead to floor slab settlement or wall cracking;
2. Prohibit cutting grooves in prefabricated floor slabs: Prefabricated slabs are hollow structures. Cutting grooves can easily sever internal reinforcement bars or cause slab fractures, posing a risk of collapse;
3. Promptly repair grooves after cutting: Fill the grooves with cement mortar and apply mesh plaster to the surface to prevent wall cracking.

III. Core Techniques for Wiring Construction

1. Route lighting wires along the base of walls: Horizontal grooving can damage the internal reinforcement bars of prefabricated slabs. Instead, groove vertically along the base of walls, with a depth not exceeding 15mm. If wiring needs to pass through floor slabs, use the pre-reserved holes in the prefabricated slabs (such as those for lighting fixtures) for threading. Direct drilling or grooving is strictly prohibited.
2. Standards for embedding conduits in self-built houses:
   • The conduit diameter should not exceed one-fourth of the slab thickness (e.g., for a 120mm-thick prefabricated slab, the conduit diameter should be ≤30mm);
   • When multiple conduits are laid in parallel, add Φ6 steel reinforcement mesh above and below the conduits, with a spacing of 100mm;
   • Limit vertical crossings to no more than two layers. At crossings, secure with steel wire and reinforce the structure.

IV. Safety Precautions

1. Secure and seal: When embedding conduits, secure joints and wire boxes with specialized clamps and seal conduit openings with tape to prevent blockage by debris during concrete pouring;
2. Inspect older houses thoroughly: Prefabricated slab houses typically have a design lifespan of 40 years. Houses that have exceeded this lifespan should be prioritized for inspection of circuit aging, especially in areas with wall cracks or floor slab deformation, to prevent wires from being severed or short-circuited due to structural movement.

Summary: Wiring in prefabricated slab houses should be carried out on the premise of not damaging the structure, using safe areas such as ceilings and the base of walls for routing. Strictly avoid cutting grooves in load-bearing walls and floor slabs, while adhering to standards for conduit embedding to ensure construction compliance and long-term safety.