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 Remendations issued by the World Trade Organization Technical Barriers to Trade (TBT)Committee. Designation:D8257/D8257M-22 INTERNATIONAL Standard Specification for Mechanically Attached Polymeric Roof Underlayment Used in Steep Slope Roofing' This standard is issued under the fixed designation D8257/D8257M:the number immediately following the designation indicates the year of original adoption or in the case of revision the year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon (e)indicates an editorial change since the last revision or reapproval. 1.Scope Shingles Used in Roofing and Waterproofing 1.1 This specification addresses mechanically attached D751 Test Methods for Coated Fabrics polymeric roof underlayment used in steep slope roofing. D1079 Terminology Relating to Roofing and Waterproofing D1204 Test Method for Linear Dimensional Changes of 1.2 The objective of this specification is to provide a Nonrigid...