How Good Is GRC's Waterproofing Performance? An In-Depth Analysis of GRC Waterproofing Technology

GRC material itself typically has a water absorption rate between 6% and 10%, making it a low-absorption material. Through reasonable mix design, a dense molding process, and effective surface treatment, GRC can fully achieve excellent waterproof and impermeability performance, meeting the protection requirements of building exterior walls. Through systematic waterproofing solutions, Qinglong GRC products perform outstandingly under all kinds of complex climatic conditions.

In the curtain wall project at Shenzhen Bay Super Headquarters Base, the Qinglong GRC waterproofing system withstood the severe test of the southern climate with frequent rain and typhoons. The project adopted an integrated waterproofing design: the material body incorporates silane-based hydrophobic agents to keep water absorption below 8%; panel joints feature a three-layer waterproof construction—an inner sealant strip, a middle drainage cavity, and outer weather-resistant sealant; drip edges and flashing plates were added at key locations such as cornices. After three full rainy seasons, no leakage whatsoever was detected on the inner side of the curtain wall system. Permeability coefficient testing showed a value of 1×10⁻¹² m/s, reaching the virtually impermeable grade.

Waterproofing Modification of the Material Body

Qinglong reduces capillary channels at the source by lowering the water-cement ratio (0.3-0.35) and optimizing particle grading to increase density. In addition, silane-based powder hydrophobic agents are added to the mix, forming a hydrophobic film on capillary pore walls after hardening, which significantly reduces water absorption and raises the impermeability grade to P6 or above.

Surface Protection Treatment Technology

For areas with higher waterproofing requirements, penetrating or film-forming waterproof coatings can be used for surface treatment. The fluorocarbon or silicone-acrylic transparent protective coatings offered by Qinglong not only deliver excellent hydrophobic performance (contact angle >110°) but also provide stain and weather resistance, maintaining long-term waterproofing effectiveness.

System Joint Waterproofing Design

Combining "material waterproofing" with "structural waterproofing" is key. Qinglong's curtain wall system designs panel joints based on the pressure-equalization cavity principle, ensuring that rainwater, after passing the first sealant line, can be smoothly drained through the cavity and preset drainage paths, preventing accumulation inside. Sealant selection is also crucial, requiring high elasticity, aging resistance, and good compatibility with GRC.

Long-Term Waterproofing Performance Verification and Maintenance

Waterproofing performance requires long-term verification. Qinglong conducts follow-up visits and water spray tests on projects completed more than 5 years ago, with data showing a waterproofing effectiveness retention rate above 95%. The company also provides regular sealant inspection and renewal services, ensuring the durability and reliability of waterproofing systems through preventive maintenance.

The waterproofing performance of GRC requires systematic assurance across materials, structural design, installation, and maintenance. What Qinglong GRC provides is not a single waterproofing product, but a complete waterproofing solution covering design, production, installation, and maintenance, ensuring the health of the building's "skin".