What Are the Waterproofing Solutions for UHPC Panels Used on Roofs?

When UHPC panels are used in roofing systems, their waterproofing treatment requires a systematic solution based on roof slope, joint construction, and functional use. In the 120,000-square-meter profiled roof project at the Hainan International Convention and Exhibition Center, Qinglong Group successfully implemented the triple-protection concept of 'structural self-waterproofing, joint seal waterproofing, and guided drainage.' This roof is one of the world's largest bidirectionally curved and twisted structures. Through the integrated design of the UHPC decorative layer with waterproofing membranes and insulation layers, it achieved the integration of decoration, structure, and waterproofing, and has maintained excellent performance through years of typhoon exposure.

The ultra-high impermeability of the UHPC material itself is the foundation of waterproofing. Its extremely low porosity (typically less than 5%) and dense microstructure give it a water absorption rate that can be below 0.5%, far lower than ordinary concrete. This means UHPC panels themselves can serve as an effective waterproofing barrier. In the roofing project of the Yangshengtang Pharmaceutical Hangzhou Industrial Park, we used 30mm-thick UHPC panels as the outermost protective and decorative layer, with an impermeability rating of P12 or above, effectively blocking liquid water penetration.

Sealed waterproofing of panel joints is key to the system. Based on joint width and deformation requirements, Qinglong adopts a multi-level sealing scheme: first, a closed-cell foam rod backer is placed in the panel joint, then filled with high-elasticity silicone sealant (movement capability ≥25%), and sealant strips are added at critical locations to form a second line of defense. For joints requiring drainage, a water-guiding channel system is designed. In the Shenzhen Pingshan High-tech Zone Comprehensive Service Center project, the precise design of panel joints ensured lasting sealing under thermal deformation.

Reinforced treatment of node details is crucial. Skylights, pipe penetrations, eaves, and other detail areas are prone to leakage. Qinglong uses specialized components such as custom stainless steel flashing plates and prefabricated formed sealant boots for treatment. In the Ouargla Hotel project in Algeria, we applied a triple waterproofing construction around all roof penetrations to ensure absolute reliability.

Scientific design of the drainage system completes the waterproofing system. Reasonable roof slope and drainage organization prevent localized water accumulation. Qinglong recommends CFD simulation analysis for major projects to optimize drainage paths. At the same time, a regular inspection and maintenance regime should be established to ensure the long-term effectiveness of the waterproofing system. Through systematic design and refined construction, UHPC roofing systems can achieve waterproofing durability matching the lifespan of the building.