ASTM D8231-2019 pdf free download

ASTM D8231-2019 pdf free download.Standard Practice for the Use of a Low Voltage Electronic Scanning System for Detecting and Locating Breaches in Roofing and Waterproofing Membranes
1. Scope
1.1 This practice describes standard procedures for using an electronic scanning system to locate membrane breaches on both horizontal and vertical surfaces to locate potential leaks in exposed roofing and waterproofing membranes. 1.2 This practice addresses the need for a detailed technical description of a scanning method and procedures that are used to test and verify the integrity of membranes. 1.3 This practice is not intended to replace visual or other methods ofinspection. It is to be used in conjunction with other methods of roof inspection when specified. 1.4 This practice requires that the detection and location equipment, procedures, and survey parameters used are cali- brated to meet established minimum leak detection sensitivity. The detection sensitivity calibration must be verified on a regular basis using the manufacturer’s procedures to assure maximum confidence in the results. 1.5 Scanning surveys can be used on membranes installed on roofs, plaza decks, pools, water features, covered reservoirs, and other roofing and waterproofing applications. 1.6 This practice is applicable for membranes made of electrically insulating materials and is used on certain moder- ately conductive membranes (see Test Method D4496). 1.7 This practice provides a description of the scanning method and equipment for locating membrane breaches using electric conductance and is intended to be used in conjunction with the manufacturer’s instructions for the proper operation and use of the equipment. 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 appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use.
4. Significance and Use
4.1 The failure to correct membrane breaches during and after its installation can cause premature failure of the mem- brane and damage to the structure. Root causes may include design deficiencies, faulty application ofthe membrane system, product failure, material incompatibility, and damage by other trades. Roof designs incorporating a waterproof membrane under overburden must be tested for breaches before overbur- den is installed. 4.2 This practice describes a low voltage (less than 50 V as defined by NFPA 70), dual sweep, scanning method using electronic leak detection to locate breaches in waterproof membranes. The method described includes testing procedures designed to provide a part of the quality assurance of roofing and waterproofing membranes. 4.3 The methods described in this practice may also be used for forensic testing of existing roofing and waterproofing membranes; however, specific limitations apply that are de- scribed later.
5. Summary of Membrane Breach Detection Using Electronic Scanning
5.1 The principle of the electronic breach detection method, as detailed in Guide D7877, is the establishment of an electrical potential between the electrically insulating or mod- erately conductive waterproofing membrane and its underlying conductive substrate. 5.2 For the low voltage method described in this practice, a controlled covering of water on the surface forms the conduc- tive path horizontally across the membrane to any membrane breach. At a breach location, an electrical path is formed through the water to the conductive substrate below. A dual sweep scanning platform with an integrated sensitive receiver detects the leakage current through a membrane breach to the substrate. 4 5.3 The substrate material directly below the membrane must be sufficiently conductive (approximately 10 4 ohms-per- square or less as determined using Test Method D4496) for the test method described in this practice to detect membrane breaches reliably. In most instances, a concrete substrate is sufficiently conductive to successfully detect membrane breaches using this method. In membrane assemblies, where the substrate is nonconductive, a conductive material can be placed directly under the membrane to facilitate testing. 5.4 This practice is applicable to moderately conductive membranes characterized by surface conductivity equal to or greater than 10 7 ohms-per-square as determined using Test Method D4496.