What Are the Waterproofing Solutions for UHPC Panels Used on Roofs? Systematic Waterproofing and Qinglong Group's Engineering Practice

Waterproofing treatment when UHPC panels are used for roofs requires building a systematic trinity solution of "self-waterproofing UHPC panels, joint sealant waterproofing, and structural drainage guidance," rather than relying on a single material. Qinglong Group has successfully applied a technical system combining "guidance, drainage, waterproofing, and sealing" in major projects such as the 120,000-square-meter wave-shaped roof of the Hainan International Convention and Exhibition Center and the roof of the Shenzhen Pingshan High-tech Zone Comprehensive Service Center. UHPC panels themselves achieve an impermeability grade of P12 or above (chloride ion diffusion coefficient ≤2.0×10⁻¹² m²/s), providing the first solid barrier for waterproofing; the core lies in panel joint treatment—we use high-elasticity silicone sealant with movement capability ≥±25%, backed by closed-cell foam rods, forming a reliable second line of defense; meanwhile, by precisely designing drainage slopes (≥2%) and installing drainage gutters and downpipe systems, rapid drainage is achieved, eliminating hidden dangers of water accumulation. After 10 years of typhoons and rainstorms, this system has achieved zero leakage.

Material Self-Waterproofing Is the Cornerstone of the System

High-quality UHPC is the foundation of waterproofing. Through maximum density packing design, Qinglong Group controls porosity below 5% and water absorption ≤3%. In coastal projects such as the Hainan Convention and Exhibition Center, we also incorporated hydrophobic agents into the UHPC surface layer, achieving a contact angle ≥110° and creating a "lotus leaf effect." Roof panels are typically no less than 20mm thick, with densified fibers added in crack-prone areas (such as panel edges) to reduce cracking at the source.

Joint Sealing Is the Lifeline of Waterproofing

Roof joints are the weak links. We strictly design joint widths according to the formula "joint width = base material width × temperature differential deformation coefficient × length + construction allowance," typically 15-25mm. Single-component or two-component silicone sealant is selected, with adhesion strength to UHPC ≥0.5MPa. During construction, the substrate must be clean and dry, with sealant application temperature between 5-40℃. For the complex curved roof of the Wuhan Han Show Theater, we ensured the sealing quality of irregularly shaped joints through custom nozzles and application techniques.

Drainage Detailing and Node Treatment

"Combining waterproofing with drainage" is key. We design systems with "drainage as primary, sealing as supplementary," setting up complete drainage cavities beneath panels to avoid siphoning. At critical nodes such as eaves, skylights, and equipment bases, multi-material composite treatments using metal flashing plates and waterproof membranes are applied, and verified through 24-hour water spray tests. Qinglong Group's systematic waterproofing solutions provide buildings with lifelong reliable protection.