Modification of Load-Bearing Walls in Prefabricated Slab Houses

The load-bearing walls of prefabricated slab houses should not be randomly demolished or modified; only non-load-bearing walls are allowed for modification. If it is necessary to judge or modify load-bearing walls, the following principles must be strictly followed:

I. Methods for Judging Load-Bearing Walls

1. Thickness Standard
   The thickness of load-bearing walls is usually ≥240mm, which is a key physical indicator for distinguishing between load-bearing and non-load-bearing walls. Non-load-bearing walls (such as partition walls) are often 120mm thick or thinner, and their thickness can be measured for preliminary judgment.

2. Floor Plan Structure Characteristics
   In rectangular floor plans, the longer side walls are mostly load-bearing walls as they need to bear the lateral transfer of floor loads. If a wall is parallel to the short side of the house and is relatively short, it may be a non-load-bearing wall.

3. Exterior Wall Attributes
   Although the exterior walls of a building do not directly bear the weight of the floors, they need to withstand the vertical loads of the walls on each floor (such as self-weight, wind loads, etc.), so they belong to the category of load-bearing structures. The integrity of the exterior walls must be preserved during modification.

4. Association with Supporting Beams
   If a wall is connected to concrete supporting beams at both ends, it must be a load-bearing wall. The supporting beams transfer the loads to the foundation through the wall, and demolition or modification will lead to structural imbalance.

II. Precautions for Modification

1. Restrictions on Modifying Non-Load-Bearing Walls
   Even for non-load-bearing walls, before demolition or modification, it is necessary to confirm whether they are lightweight partition walls (such as gypsum board or aerated concrete blocks). If the wall has embedded pipelines or is a non-load-bearing part of a shear wall structure, professional evaluation is still required.

2. Risks of Modifying Load-Bearing Walls
   Randomly demolishing or modifying load-bearing walls will damage the structural system, leading to floor subsidence, wall cracking, and even building collapse. Prefabricated slab houses rely more heavily on wall support due to their prefabricated floor components, so the risks of modification are higher.

3. Necessity of Professional Involvement
   When it comes to modifying load-bearing structures, it is essential to entrust a qualified decoration company or structural engineer to conduct on-site inspections. The remaining structural bearing capacity needs to be calculated and verified, and reinforcement plans (such as adding steel supports or carbon fiber reinforcement) should be formulated.

III. Suggestions for Compliant Procedures

1. Apply for a structural modification permit from the property management or urban construction department and submit design drawings and reinforcement plans.
2. Monitor the building settlement and cracks in real-time during the modification process. If any abnormalities are found, stop work immediately.
3. After the modification, entrust a third-party organization to conduct a structural safety assessment to ensure compliance with the requirements of the "Building Structural Load Code".

Core Principle: The structural safety of prefabricated slab houses highly depends on the load-bearing wall system. Any modification must be based on the premise of not reducing the original design bearing capacity, and unauthorized construction is strictly prohibited.