ASTM D 1970/D 1970M:2025

1.1 This specification covers polymer modified bituminous sheet materials intended for use as underlayment on roof eaves, or valleys, or both, to prevent leakage of shingle, tile, or metal roofs from water back-up due to ice dams. 1.2 These underlayment sheets have a sticky adhesive layer which is exposed by removal of a protective sheet. The top surface is suitable to work on during the application of the exposed roofing. 1.3 Table of Contents: Section Scope 1 Referenced Documents 2 Terminology 3 Workmanship, Finish, and Appearance 4 Physical Requirements 5 Sampling 6 Test Methods 7 Conditioning 7.1 Thickness 7.2 Maximum Load and Elongation at Break 7.3 Adhesion to Plywood 7.4 Thermal Stability 7.5 Flexibility at -29 °C [-20 °F] 7.6 Tear Resistance 7.7 Moisture Vapor Permeability 7.8 Capability to Seal Around Nail (Head of Water Test) 7.9 Waterproof Integrity of Side Lap Seam (Head of Water Test) 7.10 Inspection 8 Rejection and Rehearing 9 Packaging and Package Marking 10 Keywords 11 1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 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. 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.

91.100.60