Is a House with Hollow Prefabricated Slabs Good?

Houses with hollow prefabricated slabs have both advantages and disadvantages, and whether they are good depends on specific needs and conditions.

Advantages:

• Lightweight, high rigidity, and good earthquake resistance: Hollow prefabricated slabs are pre-stressed reinforced concrete floor slabs with longitudinal channels inside. This design saves materials and reduces self-weight. Compared to solid slabs of the same length and size, they are much lighter, making transportation and installation more convenient and reducing construction difficulty and costs. At the same time, they have relatively high rigidity and good earthquake resistance, enabling them to withstand natural disasters such as earthquakes to a certain extent.
• Cost-saving and guaranteed sturdiness: The design of hollow prefabricated slabs focuses more on cost savings. During the manufacturing process, it does not compromise the load-bearing capacity of the slabs, ensuring sturdiness. Moreover, due to their lightweight nature, they can further reduce the overall weight of the building, offering superior performance compared to solid prefabricated slabs.

Disadvantages:

• Poor load-bearing performance and susceptibility to damage during installation: The load-bearing performance of hollow slabs is relatively poor, making them prone to damage during installation. Additionally, after being manufactured in the factory, prefabricated slabs are transported to the site for hoisting. Mortar needs to be filled between the slabs, and node connections are required, resulting in an overall rigidity that is usually weaker than that of a fully cast-in-place structure. In the event of an earthquake or uneven foundation settlement, problems are more likely to occur at slab joints, connections, and load-bearing walls, and the structural safety is inferior to that of reinforced concrete structures.
• Quality issues in some old houses: In some prefabricated slab residential areas built in the 1980s and 1990s, due to incomplete ring beams and constructional columns, as well as less stringent standards for slab end connections and support lengths compared to current regulations, problems such as roof leakage, fine wall cracks, and poor sound insulation between floors may occur, affecting living comfort and the service life of the houses. However, the service life of prefabricated slab houses is not fixed at 30 years. Ordinary civil residences are generally designed with a 50-year working life, and prefabricated slab houses are managed under the same criteria. Whether they need to be demolished depends on professional safety assessments. Grade A and B houses can be used normally, Grade C houses require partial reinforcement, and only Grade D houses are treated as dilapidated buildings.