Water Seepage in Prefabricated Panels of House Structure

Water seepage in the prefabricated panels of house structures is caused by the characteristics of panel splicing and is commonly found in old residential buildings. It can be addressed using flexible waterproof materials.

Causes of Water Seepage

Prefabricated panels are manufactured in factories and then transported to the site for splicing. There are numerous joints between the floor panels, which serve as the main channels for water leakage. These joints are typically filled with fine aggregate concrete or cement mortar. However, this rigid connection is prone to micro-cracking or separation when subjected to temperature changes, building settlement, or vibrations, allowing water to penetrate along the micro-cracks. Additionally, the concrete of the prefabricated panels itself can develop micro-pores over time due to carbonation, freeze-thaw cycles, and other factors, further exacerbating the risk of leakage.

Treatment Approach

Covering the joint areas with flexible waterproof materials is a common treatment method. Membrane-type waterproof materials, known for their good ductility and integrity, are widely used. They can cover the entire floor surface, especially above the joints, forming a continuous waterproof barrier. During construction, the bonding method between the membrane and the substrate is crucial. The hot-melt method ensures a firm bond between the membrane and the substrate by heating, effectively preventing air pockets and detachment. Auxiliary materials such as acrylic ester coatings are often used for joint treatment, such as reinforcing the membrane lap joints or internal and external corners, to improve the reliability of the waterproof layer's seal.

Key Points of Treatment

• Precise Location of Leak Points: The joints of prefabricated panels may be hidden beneath the finishing layer, making the leak points not directly visible. Techniques such as water injection testing or infrared thermal imaging are required to confirm their locations.
• Construction Detail Handling: The cleanliness and dryness of the substrate directly affect the bonding effect of the membrane. Dust or oil stains may cause the waterproof layer to fail. For old prefabricated panel buildings, while structural settlement may have stabilized, thermal expansion and contraction due to temperature changes still occur. Using membranes with good ductility and flexible auxiliary materials is more adaptable to minor deformations of the floor panels than using rigid repair materials alone, extending the lifespan of the waterproofing.