Leakage of the Roof of a Prefabricated Slab Building

The leakage of the roof of a prefabricated slab building requires a systematic solution, focusing on addressing joint seams, base layer defects, and dynamic deformation issues. The specific causes and solutions are as follows:

Causes of Leakage

1. Seam Seepage: Prefabricated slabs are composed of multiple independent panels joined together, with the seams being through-type structures. Affected by temperature expansion and contraction and building settlement over time, these seams are prone to repeated opening and closing displacements, causing ordinary waterproof layers to crack or delaminate and forming continuous seepage channels.
2. Hidden Leakage from Base Layer Defects: The surface of prefabricated slabs is prone to unevenness, sanding, and peeling. When the base layer becomes loose and aged, rainwater can flow along the seams or cracks beneath the waterproof layer, causing the leakage point to not correspond to the actual seepage location, making local repairs difficult to cure the problem.
3. Dynamic Deformation Damaging the Waterproof Layer: Seasonal temperature differences cause thermal expansion and contraction of the prefabricated slabs. Ordinary thin-layer waterproof coatings or non-standard membranes lack sufficient tensile strength and are prone to cracking and failure due to frequent deformation, resulting in a significantly higher re-leakage rate compared to cast-in-place roofs.
4. Harsh Conditions in the Gutter Area: Gutters are prone to water and dust accumulation over time. Subjected to rainwater erosion and ultraviolet radiation, conventional waterproof materials are prone to aging, pulverization, peeling, and脱落 (should be 'detachment'), becoming high-risk areas for leakage.
5. Failure of Rigid Joint Connections in Seams: Traditional fine aggregate concrete or cement mortar filling for seams is a rigid connection method. When faced with temperature changes or vibrations, it is prone to cracking and detachment, allowing water to penetrate through micro-cracks. Over time, concrete carbonization and freeze-thaw cycles form micropores, further exacerbating leakage.

Solutions

1. Systematic Renovation: Adopt measures such as comprehensive obstacle removal,精细化 (should be 'fine') base layer repair, rigid seam filling and reinforcement, national standard thickened membrane full-area protection, and specialized exposed waterproofing reinforcement for gutters. Abandon the superficial patchwork approach of local repairs and target structural leakage weaknesses.
2. Application of Flexible Waterproof Materials: Use highly extensible membranes to cover the entire roof, especially covering the joint seams to form a continuous waterproof barrier. Hot-melt construction ensures firm adhesion between the membrane and the base layer, avoiding hollowing and detachment. Acrylic ester coatings are used for joint treatment (such as membrane overlaps, internal and external corners) to enhance sealing reliability.
3. Precise Location of Leakage Points: Confirm hidden leakage locations through water injection tests or infrared thermal imaging technology to avoid盲目 (should be 'blind') repairs.
4. Attention to Construction Details: The base layer must be thoroughly cleaned and kept dry to avoid the impact of dust or oil on adhesion. Select highly extensible materials to accommodate minor deformations in the floor slab and extend the service life of the waterproofing.