How to Deal with Joint Leakage in GRC Exterior Walls?

GRC exterior wall joint leakage is a common quality problem that requires a systematic treatment solution. Qinglong Group has summarized a four-step method of cleaning, repair, sealing and protection to effectively solve joint leakage problems and restore the waterproof function of curtain walls.

Thorough cleaning of leaking joints is the foundation of repair. Specialized tools are used to remove aged sealant, with a cleaning depth of 2/3 of the joint depth and a width of 1.5 times the joint width. Qinglong Group uses dust-free cutting machines to remove failed sealant, high-pressure air guns to clear away dust, and acetone wiping to ensure the bonding surface is clean. After cleaning, inspect the joint substrate; if there is any damage, repair and level it first with polymer mortar.

Sealant selection is crucial. High-quality silicone sealant has a movement capability of ≥25% and a durable service life of over 20 years. For projects in coastal areas, Qinglong Group selects MS sealant with better weather resistance, whose elastic recovery rate exceeds 90%. A two-pass application method is used when sealing: first inject the base sealant, then apply the surface sealant, ensuring the sealing depth reaches at least 0.5 times the joint width.

Drainage design is key to preventing leakage. Drainage channels are provided inside the joints to avoid rainwater accumulation. Qinglong Group designs joint systems based on the pressure-equalized cavity principle, using water guide strips to discharge infiltrated water in an orderly manner. Regular inspection and maintenance ensure unobstructed drainage and prevent leakage caused by blockage.