Standard: ASTM D7877-14 – Standard Guide for Electronic Methods for Detecting and Locating Leaks in Waterproof Membranes
Scope: ASTM D7877-14 describes standard procedures for using electrical conductance measurement methods to locate leaks in exposed or covered waterproof membranes. The purpose of the conductance leak location method is establishing an electrical potential between the electrically insulating waterproof membrane and the underlying substrate.
Applicable Products: Applicable for waterproofing membranes installed in roofs, plaza decks, pools, water features, covered reservoirs and other waterproofing applications.
Low Voltage Electrical Potential – A controlled covering of water on the surface forms the conductive path horizontally across the membrane to any membrane breach. At a breach location, an electrical path to the deck is formed through the water leaking to the deck below. A sensitive receiver detects the leakage current and alerts the operator.
High Voltage Electrical Potential – An electrode is swept across the surface of the membrane. The electrode is charged to a high potential relative to the deck below. At a breach location an electrical arc occurs from the electrode to the deck below. The arc discharge is electronically detected and the operator alerted.
End Result: Membrane defects (such as design deficiencies, faulty applications of the membrane system and damage by subsequent trades) are identified and corrected as soon as possible after its installation thus preventing premature failure of the membrane. If the product does not meet the performance criteria further remediation may be required to pass.