The EN 1062-3-2008 standard specifies methods for determining the water permeability of coatings and varnishes for exterior masonry and concrete. The standard is used to evaluate the water resistance performance of coatings on exterior buildings, especially with regard to the penetration of liquids such as rainwater. The standard describes in detail the test method, required equipment and Measurement conditions to assess the water resistance of coatings by testing their water permeability at a certain pressure. The standard helps to ensure that architectural coatings systems can effectively resist moisture infiltration, improve the durability and protection of buildings, and is widely used in exterior painting and quality control of Miscellaneous exterior building coating systems.