GB/T 13477.11-2017 specifies the determination method of the elongation adhesion of building sealing materials after soaking in water. It first clarifies the preparatory requirements of the test equipment and the specimen, and binds the sealing material to the substrate to make the specimen. Let the specimen be soaked in water to simulate a humid environment, and then stretch to a specific elongation and maintain it. The bonding performance is determined by observing whether the bonding between the sealing material and the substrate is firm, with or without debonding or cracking. The standard provides a basis for evaluating the Reliability of sealing materials under humid and tensile conditions, and helps to ensure the sealing effect and durability of building sealing projects in humid environments.