【国外标准】 Standard Test Method for Water Penetration of Exterior Metal Roof Panel Systems by Uniform Static Air Pressure Difference

5.1 This test method is a standard procedure for determining the resistance to water penetration under uniform positive static air pressure differences, and simulates wind driven rain imposed on sidelaps and rain that is free to drain while building a water head as it flows. The slope of the roof is significant. These factors shall be fully considered prior to specifying the test pressure difference.NOTE 1: In applying the results of tests by this method, note that the performance of a roof or its components, or both, may be a function of proper installation and adjustment. In service, the performance also depends on the rigidity of supporting construction, roof slope, and on the resistance of components to deterioration by various causes: corrosive atmosphere, aging, ice, vibration, thermal expansion and contraction, etc. It is difficult to simulate the identical complex wetting conditions that can be encountered in service, including large wind-blown water drops, increasing water drop impact pressures with increasing wind velocity, and lateral or upward moving air and water. Some designs are more sensitive than others to this upward moving water.NOTE 2: This is a test procedure. It is the responsibility of the specifying agency to determine the specimen construction, size, and test pressures after considering the method’s guidelines. Practical considerations suggest that every combination of panel thickness, span, and design load need not be tested in order to substantiate product performance.NOTE 3: This test method shall not, by itself, be relied upon to form conclusions about overall water penetration through metal roofs. A roof contains many details. Although prescribed modifications are outside the scope of this test method, an experienced testing engineer is able to use the principles presented in this test method and generate significant data by isolating specific details and measuring leakage.1.1 This test method covers the determination of the resistance of exterior metal roof panel systems to water penetration when water is applied to the outdoor face simultaneously with a static air pressure at the outdoor face higher than the pressure at the indoor face, that is, positive pressure. This test method is a specialized adaption of Test Method E331.1.2 This test method is applicable to any roof area and is intended to measure only the water penetration associated with the field of roof including panel side laps and structural connections. It does not include leakage at openings or perimeter or any other details.1.3 This test method is limited to specimens in which the side seams and attachments are clearly visible and in which the source of leakage is readily determined. Composite systems in which the source cannot be readily determined are outside the scope of this test method.1.4 The proper use of this test method requires a knowledge of the principles of pressure and flow measurement.1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.6 The text of this test method references notes and footnotes excluding tables and figures, which provide explanatory material. These notes and footnotes shall not be considered as requirements of the test method.1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see 7.1.1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.