Prefabricated Balcony Panel of Old Houses

Key points regarding the prefabricated balcony panel of old houses are as follows:

Structural Types

Houses from the 1980s are mostly brick-concrete structures, with two types of balcony slabs: prefabricated slabs and cast-in-place slabs. Different structural balcony slabs vary in load-bearing capacity and stability, which also affects the design, construction, and subsequent renovation of balcony panels. For example, prefabricated balcony slabs are installed piece by piece during construction, and their overall integrity and earthquake resistance may be slightly weaker compared to cast-in-place slabs; while cast-in-place slabs are formed as a whole by pouring concrete on-site, with relatively better structural performance.

Panel Renovation

During the renovation process, there are cases where old-style prefabricated balcony railings are removed and replaced with cast-in-place imitation stone railings. The specific renovation methods are as follows:

• Mold Treatment: Apply waste engine oil inside the mold. The purpose of this step is to facilitate subsequent demolding, allowing the poured railing to be smoothly removed from the mold and ensuring the integrity and aesthetics of the railing surface.
• Rebar Placement: Use an electric drill to drill holes at the corresponding positions, then insert rebars and tie a rebar mesh every 20 centimeters. Rebars play a role in enhancing the load-bearing and tensile capacities in concrete structures. Reasonable rebar placement ensures that the cast-in-place imitation stone railing has sufficient strength and stability to withstand external forces such as people leaning on it and wind.
• Mold Installation and Fixation: After placing the railing mold, press the mold with a horizontal rebar and tie it securely. The purpose of this is to prevent the mold from shifting during concrete pouring, ensuring that the shape and dimensions of the railing meet the design requirements and that the poured railing has a neat and standardized appearance.

Precautions for Load-Bearing Walls

In old residential areas with prefabricated balconies, the wall below the window is a crucial load-bearing wall, acting like a counterweight to prevent the balcony from overturning. Therefore, the wall below the window must not be removed without permission. Removing the wall below the window will disrupt the overall force balance of the balcony, reducing its load-bearing capacity and increasing the risk of balcony overturning, seriously threatening the lives of the occupants. When carrying out any renovation involving the balcony structure, the role of the load-bearing wall must be fully considered to ensure the structural safety of the balcony.