Renovation of Prefabricated Slab Floor Houses

Before renovating a prefabricated slab floor house, a safety assessment must be conducted first, and the decision to renovate should be based on the assessment results. Details are as follows:

I. Safety Assessment as a Prerequisite Prefabricated slab houses built from the 1970s to the 1990s have floor slabs made of prefabricated hollow slabs spliced together, resulting in poor integrity and weak earthquake resistance. The load-bearing walls are mostly brick walls. According to the "Guangzhou Urban Dilapidated Housing Renovation Implementation Measures (Trial)" issued by Guangzhou in 2024, houses must be assessed by professional institutions:

• Grade B or generally damaged houses: The structure is basically safe. Owners can voluntarily apply for renovation and may carry out moderate renovation, but must avoid damaging the load-bearing structure.
• Grade C, Grade D, severely damaged houses, or dangerous houses: Mandatory renovation is required, and blind renovation is not allowed. Unauthorized renovation may lead to losses in renovation costs due to structural issues of the house and even pose safety risks. Currently, about 15% of prefabricated slab houses nationwide are rated as Grade D dilapidated houses, while over 50% are rated as Grade A and Grade B (basically safe structures).

II. Renovation Restrictions to Note

1. Floor slab gap issues: There are gaps between the prefabricated slab floor slabs. If the gap filling during construction is not tight or the material quality is poor, water leakage is likely to occur later, especially in water-using areas such as kitchens and bathrooms. Before renovation, check the gap treatment and, if necessary, re-fill the gaps and apply a waterproof layer.
2. Slot-cutting restrictions: Excessive slots cannot be cut in prefabricated slabs. During renovation and transformation, avoid cutting a large number of slots or drilling holes in the floor slabs to prevent damaging the structural stability. If pipeline laying is required, surface slot-cutting or open installation methods should be preferred.
3. Protection of load-bearing walls: The load-bearing walls of prefabricated slab houses are mostly brick walls. During renovation, it is strictly prohibited to remove or modify the load-bearing structure; otherwise, serious consequences such as house collapse may occur.

III. Handling of Special Cases If the house is assessed as Grade C or Grade D, it is necessary to wait for policy support or apply for original demolition and reconstruction. Unauthorized renovation is not allowed. For example, some regions provide subsidies or unified planning for the renovation of dilapidated houses. Owners can pay attention to local policy updates and improve their living conditions through legal channels.