Waterproofing Installation for Prefabricated Slab Houses

The installation of waterproofing layers for prefabricated slab houses requires systematic treatment tailored to their structural characteristics, with core measures including base layer repair, slab joint reinforcement, full-area waterproofing, gutter strengthening, and standardization of materials and processes.

1. Base Layer Defect Repair
The surface of prefabricated slabs often exhibits issues such as unevenness, sanding, peeling, and fine honeycomb cracks due to construction or aging. These defects can serve as hidden pathways for rainwater infiltration, leading to water migration between the waterproofing layer and the base layer. During repair, it is essential to thoroughly remove loose layers and use polymer cement mortar or specialized repair materials for precise leveling, ensuring that the base layer flatness error is ≤2mm to prevent subsequent waterproofing layer cracking due to stress concentration.

2. Rigid Filling and Reinforcement of Slab Joints
Slab joints are a primary risk point for leakage in prefabricated slab houses. Due to temperature-induced expansion and contraction, as well as building settlement, slab joints repeatedly open and close. If only flexible materials are used for filling, they are prone to cracking and failure. It is necessary to first clean debris from the slab joints using high-pressure air, then inject epoxy resin or polyurethane rigid sealant to form a continuous elastic sealing layer. Finally, a non-woven fabric reinforcement layer is applied to the surface to enhance tear resistance.

3. Full-Area Waterproofing Layer Installation
Traditional partial repairs or surface coating processes cannot fundamentally resolve leakage issues. Instead, a national standard-compliant thickened (≥4mm) SBS modified bitumen membrane should be used for full-area铺设 (installation). The membrane should be applied using the hot-melt method to ensure full adhesion to the base layer, with an overlap width of ≥100mm. Additional layers should be installed to cover vulnerable areas such as internal and external corners and pipe roots, forming a 'skin-like' waterproofing system that eliminates water migration risks.

4. Specialized Waterproofing Reinforcement for Gutters
Gutters, as concentrated drainage areas, are subject to long-term rainwater scouring and ultraviolet exposure, causing ordinary waterproofing materials to age and powder easily. It is necessary to use exposed TPO waterproofing membranes or polyurea coatings, which offer weather resistance of over 15 years. During construction, the membrane should extend to the top of the parapet wall and be secured with metal strips to prevent rainwater backflow.

5. Standardization of Materials and Processes
Select waterproofing materials with a tensile strength of ≥8MPa and an elongation at break of ≥400% (such as Oriental Yuhong national standard genuine products) and strictly adhere to the standardized process of 'base layer treatment → node reinforcement → large-area construction → water immersion test → finished product protection'. For example, the Phase I project of Zhonghuan Jiayuan in Putuo District, Shanghai, successfully resolved repeated roof leakage issues by implementing the above solution combined with a 5-year warranty, validating the effectiveness of systematic waterproofing.