Floor Leakage in Prefabricated Slab Houses
Floor leakage in prefabricated slab houses primarily stems from the failure of joint treatment and material aging, requiring repair with flexible waterproof materials and attention to construction details.
Analysis of Leakage Causes
The floor slabs of prefabricated slab houses are manufactured in factories and then assembled on-site, resulting in numerous joints between the slabs. Traditional joint-filling materials, such as fine aggregate concrete or cement mortar, form rigid connections that are prone to cracking or detachment under the influence of temperature changes, building settlement, or vibrations, creating pathways for water infiltration. Additionally, the long-term exposure of the prefabricated slab concrete to carbonation and freeze-thaw cycles leads to the formation of micro-pores within the material, further exacerbating the risk of leakage. Older residential buildings (constructed between 1990 and 2010) are particularly prone to widespread leakage issues due to the failure of joint sealing, aging of waterproof layers, and structural settlement, with common examples including water seeping through cracks into the ceiling below when mopping the floor.
Core Treatment Approach
To address the leakage problem, flexible waterproof materials should be used to cover the joint areas, forming a continuous waterproof barrier. Membrane materials, such as SBS modified bitumen membranes, are widely used on the floor surface and above the joints due to their excellent elongation and overall integrity. During construction, the hot-melt method is employed to heat the membrane and the substrate, ensuring a firm bond and preventing hollow spaces or detachment. Acrylic ester-based coatings and other auxiliary materials are used for joint treatment (e.g., at membrane overlaps, internal and external corners) to enhance sealing reliability.
Key Construction Steps
Precise Leak Point Location: Since joints may be covered by finishing layers, water injection tests (injecting water onto the floor to observe leakage points) or infrared thermal imaging (detecting temperature differences to locate hidden cracks) are necessary to accurately identify leak locations and avoid盲目 (unnecessary) construction.
Substrate Preparation and Material Selection: The substrate must be thoroughly cleaned of dust and oil and kept dry; otherwise, it will affect the bonding effect of the membrane. For older buildings subject to continuous thermal expansion and contraction, membranes with good elongation (e.g., polyester-based membranes) and flexible auxiliary materials should be prioritized over rigid repair materials to accommodate minor floor slab movements and extend the service life of the waterproofing.
Construction Detail Control: The membrane should be laid to cover the entire floor surface, especially above the joints; the overlap width should comply with regulations (typically ≥80mm) and be reinforced with coating for sealing. After construction, a closed water test should be conducted to verify the waterproofing effectiveness.
Through systematic treatment, the leakage problem in prefabricated slab houses can be effectively resolved. However, regular inspections and maintenance are required to promptly repair newly emerged cracks or aged areas.
