ASTM D7877-24 PDF

SIGNIFICANCE AND USE 4.1 The failure to correct membrane defects during and as soon as possible after its installation can cause premature failure of the membrane. Problems include design deficiencies, faulty application of the membrane system, and damage by subsequent trades.4 Roof designs incorporating a waterproof membrane under overburden such as a vegetative roof, insulation layer, wear-course, or topping slab greatly exacerbate the problem of leak locating. 4.2 This guide describes methods for using electric conductance testing to locate breaches in waterproof membranes.5 The methods described include testing procedures designed to provide a part of the construction quality control of membrane installations. 4.3 The methods described in this guide may also be used for integrity or forensic testing of existing waterproof membranes; specific limitations apply. 4.4 The electric conductance methods described in this guide require a conductive substrate under the membrane to serve as a ground return path for the test currents. In roof assemblies where the membrane is installed over electric insulating material such as insulating foam or a protection board, or both, the electric path to any conductive deck is interrupted. The situation can be remedied by placing a conductive material directly under the membrane. The conductive material provides the return path for the test currents. SCOPE 1.1 This guide describes standard procedures for using electrical conductance measurement methods to locate leaks in exposed or covered waterproof membranes. 1.2 This guide addresses the need for a general technical description of the current methods and procedures that are used to test and verify the integrity of waterproof membranes. 1.3 This guide is not intended to replace visual, infrared, or other methods of inspection. It is to be used in conjunction with other methods of roof inspection when specified. 1.4 This guide recommends that the leak location equipment, procedures, and survey parameters used are calibrated to meet established minimum leak detection sensitivity. The leak detection sensitivity calibration should be verified on a regular basis according to the manufacturer’s recommendations. 1.5 Leak location surveys can be used on waterproofing membranes installed in roofs, plaza decks, pools, water features, covered reservoirs, and other waterproofing applications. 1.6 The procedures are applicable for membranes made of materials such as polyethylene, polypropylene, polyvinyl chloride, bituminous material, and other electrically insulating materials. 1.7 This guide provides a general description of the equipment and methods for locating membrane breaches using electric conductance. Refer to the manufacturer’s instructions for the proper operation and use of the equipment described in this guide. 1.8 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. 1.9 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.