Significance and Use
5.1 This test method is a standard procedure for determining windload resistance of rigid plastic siding under specified uniform static pressure difference. This typically is intended to represent the effects of wind loads on exterior building surfaces. The actual loading on building surfaces is quite complex, varying with wind direction, time, height above ground, building shape, terrain, surrounding structures, and other factors.
5.2 Design wind pressure is derived for specific geographical locations from wind velocity maps prepared by various agencies and found in references such as ASCE 7, the International Residential Code, International Building Code or other sources. For additional detailed information relating to the use of this test method for evaluation of wind load resistance, refer to Annex A1 of the standard specification appropriate for the type of polymeric siding.
NOTE 2: In applying the results of this test method, note that the performance of rigid PVC siding is a function of installation, and the specimen may or may not truly represent the actual application. In service, performance will also depend on the rigidity of supporting construction, and on the resistance of other components to deterioration by various causes, to thermal expansion and contraction, etc.
Scope
1.1 This test method describes methods for testing and evaluating windload resistance of rigid plastic siding when fastened in accordance with Practice D4756, specific product standard specifications, or in accordance with manufacturer’s installation instructions.
1.2 The proper use of this test method requires a knowledge of the principles of pressure measurement.
1.3 This test method describes the apparatus and the procedures to be used to determine an average maximum sustained static test pressure, or ultimate test pressure values, or both, with static pressure applied uniformly to a specimen.
NOTE 1: There is no known ISO equivalent to this test method.
1.4 The values expressed in inch-pound units are to be regarded as the standard. The SI equivalents in parentheses are for information only.
1.5 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 precautionary statements, see Section 7.
1.6 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.