Wiring on the Roof of Prefabricated Slab Houses
When laying wires on the roof of a prefabricated slab house, priority should be given to utilizing the hollow pipes inside the prefabricated slabs or the ceiling space. It is strictly prohibited to cut grooves in the prefabricated slabs, and when connecting wires, the grooves cut in the walls should be handled in a standardized manner.
Utilizing the Hollow Pipes Inside the Prefabricated Slabs
The structure of prefabricated slabs usually includes pipes that lead directly to the hollow spaces. These pipes serve as natural channels for concealed wiring. Insert the sheathed wires into these pipes to achieve concealed wiring while avoiding damage to the main structure of the prefabricated slabs. Select sheathed wires that comply with national standards, ensuring that the outer insulation material is aging-resistant and has satisfactory flame-retardant properties to prevent insulation failure due to moisture or temperature changes inside the pipes. Before inserting the wires, clear any debris from the pipes to avoid scratching the wire insulation. After insertion, check the sealing at both ends of the pipes to prevent pests and rodents from entering and damaging the wiring.
Wiring Through the Ceiling Space
If the roof does not have hollow pipes, the ceiling space can be used for wiring. Use PVC or metal wire conduits, insert the wires into the conduits in a standardized manner, and then secure them to the ceiling joists, ensuring that the conduits run straight and are tightly connected. The fixing spacing of the wire conduits should be controlled within 0.8-1 meter to prevent the conduits from sagging and pressing on the wires or affecting the stability of the ceiling. The insulation performance of the wires should be thoroughly tested, especially in ceiling spaces that may be damp or have high temperatures. Choose insulation materials with higher temperature resistance ratings and leave sufficient length for easy maintenance in the future.
Strictly Prohibiting Cutting Grooves in the Prefabricated Slabs
Prefabricated slabs have a hollow structure. Cutting grooves will directly sever the internal steel bars or damage the integrity of the slab, reducing the load-bearing capacity of the floor slab and even posing a risk of collapse. If wires need to be connected indoors, grooves should be cut in the walls, but avoid load-bearing walls and the connection areas between the prefabricated slabs and the walls. The depth of the grooves should be controlled within the thickness of the concrete cover protecting the steel bars in the walls (usually not exceeding 15mm), and the width should be sufficient to accommodate the wire conduits to avoid excessive damage to the wall structure. After cutting the grooves, fill them with cement mortar and apply wire mesh and plaster on the surface to prevent cracking and restore the original strength of the wall.
Standardized Operation for Connecting Wires by Cutting Grooves in the Walls
When cutting grooves in non-load-bearing walls, use professional groove-cutting tools to ensure that the edges of the grooves are neat and the depth is uniform. The wire conduits should be laid using the "live wire technique," meaning that the radius of the curved sections of the conduits should be no less than six times the diameter of the conduits to facilitate the replacement of wires in the future. After inserting the wires into the conduits, leave a margin of more than 15cm. Connect the wire ends using junction boxes and wrap them tightly with insulating tape. All wiring should be mapped and archived to facilitate locating the wiring during future maintenance or renovation.
