JIASHILI Explains Core Indicators of Coating Weather Resistance: How to Judge Scrub Resistance and Actual Quality?

<h2>Common Classifications and Testing Standards of Coating Weather Resistance</h2><p>Many exterior wall decoration contractors have faced this headache: coatings showing powdering and fading after just two years of use, which is mainly due to insufficient weather resistance. Currently, the commonly used classification of weather resistance in the industry follows the GB/T 1865-2009 standard, divided into three grades: grade 1, grade 2, and grade 3. Grade 1 weather resistance requires the coating to withstand 3,000 hours of ultraviolet radiation in artificial accelerated aging tests, with a color difference ΔE not exceeding 5 and adhesion rating reaching level 0. Only coatings of this grade can be used on exposed areas such as the exterior walls of high-rise residential buildings.</p><img src="/images/news/news-10-1.png" alt="Weather resistance aging test equipment in the laboratory, conducting ultraviolet irradiation aging tests on samples" /><p>JIASHILI's R&D team specifically optimized the resin content of weather-resistant formulations last year to suit the rainy and humid climate in southern China, extending the aging duration of grade 1 weather-resistant coatings from 3,000 hours to 3,500 hours, a leading figure among peers. During testing, we found that coatings using the new weather-resistant resin had a corrosion rate 42% lower than ordinary coatings in simulated coastal salt spray environments, fully meeting the needs of outdoor use in coastal areas.</p><h2>Scrub resistance is an important reference for judging coating weather quality</h2><p>Many people mistakenly think scrub resistance only relates to wall cleaning, but it is actually directly related to weather resistance. According to the industry standard JC/T 1042-2023, high-quality weather-resistant coatings must withstand over 5,000 scrub cycles. This value reflects the coating's ability to resist external physical wear—such as scratches from branches, erosion by rainwater, or friction during daily cleaning—without peeling or discoloration.</p><p>A client in Hangzhou previously reported that the coating on his old residential building's exterior wall peeled off after two years. Our on-site inspection revealed he had used ordinary grade 2 coatings with only about 2,000 scrub cycles, unable to withstand the humidity of the plum rain season and daily sand abrasion in southern China. After switching to JIASHILI's grade 1 weather-resistant coatings, the wall has maintained its bright color for over three years without peeling even in corners.</p><img src="/images/news/news-10-2.png" alt="Exterior wall coated with JIASHILI's high-quality coatings, with a smooth surface and no fading, demonstrating remarkable weather resistance" /><h2>Details to note when purchasing weather-resistant coatings</h2><p>To select truly durable weather-resistant coatings, do not rely solely on vague claims like "UV-resistant" or "weatherproof" made by sellers. Always ask to see third-party test reports and check whether the three core indicators—color difference, adhesion, and scrub resistance—meet the standards. Additionally, note that climate conditions vary greatly by region; for example, the amount of sand in northwestern China is much higher than in southern China, so choose region-specific customized coatings when purchasing.</p><p>As a brand with 20 years of experience in the coating industry, JIASHILI invests over 6% of its annual revenue in R&D to continuously improve the performance of weather-resistant formulations. If you need weather-resistant coatings for outdoor projects, feel free to contact our technical team at any time. We will recommend the most suitable products based on the climate characteristics of your project location and help you avoid problems caused by substandard weather resistance.