How to Handle Joint Leakage in GRC Exterior Walls: Cause Analysis, Solutions and Prevention Measures

In the field of architectural decoration, GRC (Glass Fiber Reinforced Concrete) is widely used in the facade systems of high-end projects such as grand theaters, commercial complexes, and landmark buildings, thanks to its lightweight, high-strength properties and rich design possibilities. However, joint leakage has become a common hidden problem affecting the durability and aesthetics of GRC facades. As an industry leader with 28 years of full-chain experience in UHPC/GRC/GRG/GRP materials, Qinglong Group draws on more than a thousand engineering projects to provide designers and owners with professional technical support—from cause diagnosis and systematic solutions to long-term prevention.

Core Causes of GRC Facade Joint Leakage

The root causes of joint leakage often span the entire process of design, production, and construction. At the material level, if GRC components are not cured to standard, resulting in excessive moisture content, later shrinkage cracking can easily occur. During construction, improper sealant selection and filling techniques (such as failing to use weather-resistant silicone sealant or air bubbles in the sealant) are direct triggers; environmental factors such as thermal expansion and contraction caused by temperature changes and settlement of the base structure can further aggravate joint deformation. Take a commercial complex project as an example: because the deformation difference between GRC panels and the base wall was not taken into account, the joints opened up to 3mm under low winter temperatures, allowing rainwater to seep in.

Qinglong's Systematic Solutions for GRC Joint Leakage

For different leakage scenarios, Qinglong has established a tiered treatment system. For minor water seepage, a "surface repair + sealant reinforcement" solution is adopted: after removing the old sealant, Qinglong's custom GRC-specific repair mortar is used to fill the gaps, then backer rods are inserted and high-modulus silicone sealant is applied, ensuring a bond strength of ≥1.5MPa between the sealant and the substrate. Complex leakage requires "structural reinforcement + waterproofing upgrade"—for example, in a landmark project, UHPC waterproof baffles (flexural strength ≥20MPa) were added inside the joints, combined with double-layer sealant strips to form a composite waterproof barrier, and no further leakage occurred after three rainy seasons.

Full-Chain Prevention: Qinglong Standards from Design to Maintenance

As a contributing organization to the Technical Standard for Building Application of Glass Fiber Reinforced Cement (GRC), Qinglong integrates the concept of prevention into the entire process. In the design phase, BIM technology is used to simulate temperature deformation, reserving expansion joint widths of ≥5mm; in production, the moisture content of GRC components is strictly controlled at ≤8%, with 28-day standard curing before leaving the factory; during construction, a "3D laser positioning + modular installation" technique is implemented to ensure joint tolerances of ≤2mm. In after-sales maintenance, a joint inspection system every two years has been established, using endoscopes to check sealant aging, enabling early detection and early treatment of leakage problems.

From the hyperbolic GRC facade of a convention and exhibition center in Guangzhou to the European-style decorative moldings of a high-end hotel in Malaysia, Qinglong has leveraged its full-chain advantages in detailed design, manufacturing, construction and installation, and after-sales maintenance to successfully solve leakage problems for over 2 million ㎡ of GRC facades. Moving forward, Qinglong will continue its mission of "creating beautiful architecture," promoting the high-quality application of GRC materials in the field of architectural decoration through technological innovation and standards leadership.