Opening of Prefabricated Slabs on the Roof of Old Houses
The opening of prefabricated slabs on the roof of old houses requires careful handling. Generally, it is not advisable to make openings randomly. If openings must be made, specific methods should be followed, and multiple factors should be considered.
Opening Methods
Generally, sheath wires are used. A groove that can accommodate the sheath wires is cut on the ceiling, the sheath wires are fixed inside the groove, and then the groove is filled with gypsum powder putty. The depth of the groove on the wall is generally about 3 centimeters, and the width should be sufficient to accommodate the wire conduit. When cutting grooves on the ceiling, consideration can be given to doing so in the direction of the room's width. If there is a pre-buried wire box in the middle of the ceiling, this box and wire conduit can be utilized. However, for the prefabricated slabs of old houses, many electricians are reluctant to cut grooves due to safety concerns. Because the prefabricated slabs have a small span, they are prone to sinking and leaking over time. Their structure is relatively simple, and their safety is not ideal. The vibrations generated by cutting grooves for wires may damage the prefabricated slabs and even penetrate the floor slab, affecting the occupants downstairs.
Impact on Load-Bearing Capacity
The direction of the opening has different impacts on the load-bearing capacity. If grooves are cut along the direction of the floor slab (longitudinal seams), there is basically no impact on the load-bearing capacity. However, if grooves are cut perpendicular to the length of the floor slab at the bottom of the slab, it will have an adverse impact on the load-bearing capacity of the floor slab, especially in the event of an earthquake, which may lead to serious consequences. When cutting grooves, a cutting machine should be used, and it is best not to use a hammer drill to prevent excessive vibrations from affecting the ceiling. Generally, it is fine as long as the grooves do not reach the steel bars. If the groove-cutting method is incorrect, such as excessive force or non-standard operation, it will affect the prefabricated slabs.
Attribution of Responsibility (If Damage is Caused by Construction Such as Making Openings)
The attribution of responsibility should be judged based on the specific situation. The general principle is that whoever causes the damage is responsible. If a decoration worker causes the prefabricated slab on the ceiling of the downstairs to crack due to improper construction operations, such as excessive knocking or drilling, the decoration worker shall be held responsible. If the worker is employed by a decoration company, the decoration company shall be liable for compensation. If the decoration company is hired by the homeowner and the homeowner has made mistakes in selecting the decoration company, such as failing to review the decoration company's qualifications or failing to sign a formal contract, the homeowner may be required to bear supplementary responsibility. If the homeowner carries out the construction themselves and causes the prefabricated slab on the ceiling of the downstairs to crack due to improper construction, the homeowner shall bear full responsibility for compensation.
