This standard specifies the test methods for the weather resistance of external thermal insulation composite systems (ETICS) applied to building façades. Its core principle involves simulating extreme climatic conditions—primarily through two consecutive phases: high-temperature water spray cycles and heating-freezing cycles—to assess the durability and stability of the system in response to long-term exposure to sunlight, rain, and temperature fluctuations. After completing the test process, key performance indicators of the specimens, such as tensile bond strength and impact resistance, must be inspected and evaluated. Implementing this standard requires specialized testing instruments, primarily a weather resistance test chamber (also known as a climate simulation test chamber), which can precisely control temperature, humidity, and simulate spray procedures.