What methods are typically used for waterproofing GRC curtain walls?

Waterproofing of GRC curtain walls is key to ensuring the sealing performance of a building and requires a systematic waterproofing strategy. Through 28 years of project practice, Qinglong Group has developed a waterproofing system featuring "construction-based waterproofing as the primary approach, supplemented by material waterproofing," achieving reliable waterproofing results through panel joint design, sealant selection, and drainage detailing.

The structural design of panel joints is the foundation of waterproofing. Qinglong Group designs panel joints based on the pressure-equalized cavity principle, discharging infiltrated water through water guides and weep holes. In the Shenzhen Pingshan High-tech Zone Comprehensive Service Center project, drip edges were installed at the horizontal joints of GRC panels, and double sealing was applied at vertical joints, forming a complete drainage system. Panel joint widths are determined by thermal deformation calculations, typically 8-15mm, ensuring sealing effectiveness while allowing the necessary deformation.

The choice of sealing material directly affects waterproofing durability. Qinglong Group prefers silicone or modified silicone sealants with a movement capability of ±25% or greater and a weathering service life exceeding 20 years. In Hainan's hot and humid environment, sealants must also pass UV resistance and anti-mold tests. The application process is equally critical: backer rods are used to control the shape of the sealant joint, ensuring effective adhesion between the sealant and the substrate.

Waterproofing at node locations requires special treatment. At junctions between GRC and different materials such as windows and stone, Qinglong Group adopts multiple waterproofing measures. In the Shanghai Qingpu R&D Base project, we designed a node detail combining stainless steel flashing with sealant, effectively preventing rainwater penetration. For pipes passing through panels, compressible sealing collars are used for sealing.

The internal drainage system is the final safeguard of waterproofing. Qinglong Group installs drainage cavities behind panels, channeling any possible leaked water out through designed drainage paths. Regular inspection and maintenance are also essential to the effective operation of the waterproofing system. This systematic waterproofing design enables GRC curtain walls to maintain good waterproofing performance under various climatic conditions.