Characteristics of Prefabricated Roof Houses

Prefabricated roof houses are characterized by fast construction speed and low cost, but relatively weak integrity, waterproofing, and load-bearing capacity.

Construction Characteristics: The prefabricated slabs of prefabricated roof houses are uniformly produced in advance according to dimensions. They are easy to lay, enable fast construction, and have relatively low costs. When building houses in rural areas, people usually calculate the required number of prefabricated slabs in advance and then place orders at prefabricated slab factories for direct use during construction. In addition, most components of prefabricated roof houses are prefabricated in factories, and only assembly is required on-site. The construction period is usually more than 50% shorter than that of traditional buildings. For example, a 100-square-meter prefabricated house may take only 1-2 months to complete, while a traditional brick-and-concrete structure house may take more than 6 months.

Performance Characteristics:

• Integrity: The overall earthquake resistance is relatively poor. Prefabricated slabs are formed by splicing plates together, and the overall stiffness is usually weaker than that of fully cast-in-place structures. In the event of an earthquake or uneven foundation settlement, problems are more likely to occur at slab joints, connections, and load-bearing walls.
• Waterproofing: The waterproofing performance is relatively poor, and it is not recommended to use prefabricated roofs in kitchen and bathroom areas. There are certain gaps between prefabricated slabs, which can easily cause roof leaks. For prefabricated slab roofs, due to significant structural settlement, if only rigid waterproofing materials are used, cracks may occur due to settlement; if only flexible waterproofing materials are used, they may age and decompose due to acid rain and ultraviolet radiation, resulting in a relatively short waterproofing lifespan.
• Load-Bearing Capacity: The load-bearing capacity is relatively weak. Improper construction can easily lead to cracks in the building, and it is not suitable for heavy ceiling installations and partition wall modifications.

Other Characteristics: Prefabricated roof houses were a common form of welfare housing distribution in the early 1990s and before, benefiting from the fast construction and cost-effectiveness of prefabricated slabs. However, commercial housing after 1998 generally uses cast-in-place slabs. In addition, ordinary civil residential buildings are usually designed with a service life of 50 years, and prefabricated slab houses are also managed according to the same standard. Thirty years is not a mandatory scrapping line, and whether to demolish them depends on professional safety appraisals. According to the classification of housing safety appraisals, Grade A and Grade B houses can be used normally, Grade C houses require local reinforcement, and only Grade D houses are treated as dilapidated buildings.