How to Waterproof UHPC Curtain Walls in Humid Regions?

Waterproofing design for UHPC curtain walls in humid regions requires a systematic strategy of "drainage first, combining waterproofing with drainage, multiple lines of defense, and comprehensive treatment." In the Hainan International Convention and Exhibition Center project, Qinglong Group successfully solved the waterproofing challenge of a 120,000-square-meter roof by combining the pressure-equalization cavity principle with multi-layer sealing technology. Scientific waterproofing design is the fundamental guarantee for a building's durability in humid environments.

Panel joint waterproofing is the first line of defense in curtain wall waterproofing. Qinglong adopts a "double sealant joint" design: weather-resistant sealant is applied on the outside as the primary waterproofing layer, while foam rod backer and sealant are set on the inside, forming a reliable waterproofing system. The width-to-thickness ratio of the sealant joint is controlled at 2:1 to ensure sufficient deformation capacity. In Hainan's hot and humid environment, we select medium-modulus silicone sealant with a movement capability of over ±25%, able to accommodate the thermal expansion and contraction of UHPC panels.

Pressure-equalization cavity design is an effective measure to prevent rainwater penetration. By providing an air layer behind the panels, the pressure inside the cavity is balanced with the outdoor pressure, eliminating the driving force for rainwater penetration. In the Nanning New Media Center project, Qinglong organically integrated pressure-equalization cavities with drainage holes, ensuring that any rainwater that occasionally enters can be discharged quickly. All drainage holes are fitted with insect screens to prevent clogging that would compromise drainage performance.

Waterproofing at joint locations requires special attention. The dedicated joint waterproofing kits developed by Qinglong include preformed rubber sealing strips, stainless steel water deflectors, and more. At the connections between panels and window frames, and between panels and structural walls, we adopt multi-layer waterproofing construction to ensure absolute reliability. Waterproofing treatment of embedded parts is equally critical: all bolt holes are sealed with sealant to prevent water vapor from penetrating along metal components.

Regular maintenance is a vital part of maintaining waterproofing performance. Qinglong recommends a comprehensive inspection of the sealant every 3 years, with partial repair or replacement every 5 years. Establishing a complete maintenance archive that records each inspection and repair provides a guarantee for the curtain wall's long-term use. Only by organically integrating design, construction, and maintenance can the excellent performance of UHPC curtain walls in humid environments be ensured.