GB/T 13477.20-2017 specifies the method for determining the contamination of building sealing materials. The standard specifies the materials required for the test, such as specific adjacent substrates, and details the operation of combining the sealing material and the substrate as required. Under certain time and environment conditions, observe the contamination of the sealing material to the substrate, including whether bleeding occurs, stain diffusion and other phenomena. Through this measurement, the impact of building sealing materials on the surrounding materials in actual use can be effectively evaluated, providing a scientific basis for ensuring the cleanliness of the building Appearance and ensuring the suitability of the sealing material to the surrounding environment.