Water Leakage in Prefabricated Panel Structure Houses

Water leakage in prefabricated panel structure houses mainly stems from the joints between panels and defects in the concrete itself, and its treatment requires a combination of flexible waterproofing materials and precise construction.

Sources of Water Leakage

Prefabricated panels are components manufactured in a factory and then assembled on-site, resulting in numerous joints between floor panels. Although these joints are filled with fine aggregate concrete or cement mortar, the rigid connections are prone to cracking or separating due to temperature changes, building settlement, or vibrations, creating pathways for water leakage. Additionally, the concrete in prefabricated panels can develop micro-pores over time due to carbonation and freeze-thaw cycles, further exacerbating the risk of leakage.

Treatment Approaches

1. Covering Joints with Flexible Waterproofing Materials Membrane-type waterproofing materials, such as SBS modified bitumen membranes, are preferred due to their excellent elongation and integrity. These materials can cover the entire floor surface, with particular emphasis on treating the joint areas to form a continuous waterproof barrier. During construction, attention should be paid to:

• Bonding Method: Hot-melt application ensures a firm bond between the membrane and the substrate, preventing air pockets or detachment.
• Joint Treatment: Acrylic ester coatings are used at membrane overlaps, internal and external corners, and other vulnerable areas to enhance sealing.

2. Precise Location of Leak Points The joints between prefabricated panels may be covered by finishing layers, making it necessary to confirm leak points through professional methods:

• Water Injection Test: Continuously inject water into suspicious areas and observe the leakage location indoors.
• Infrared Thermography: Utilize temperature differences to detect hidden leakage points, improving location efficiency.

3. Control of Construction Details

• Substrate Preparation: Thoroughly clean dust and oil stains, ensuring dryness (moisture content ≤ 9%), otherwise, the membrane may delaminate.
• Material Selection: For older buildings subject to continuous thermal expansion and contraction, select membranes with good elongation (such as polyester base membranes) and flexible accessories to accommodate minor floor panel deformations and extend the waterproofing lifespan.

Precautions

Rigid repair materials, such as cement mortar, are only suitable for static cracks and have limited effectiveness against dynamic cracks (such as those caused by temperature deformation). During treatment, priority should be given to a combined approach of a flexible waterproofing layer and joint reinforcement. Regularly inspect the integrity of the waterproofing layer and promptly repair any local damage.