Innovations in Green Roofing

Prime Roofing & Exteriors

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Adhering to the ASTM Standards is Critical for Effective Quality Assurance

We are all in an amazing business. Working together, we deliver wonderful outdoor living areas that provide incredible benefits to our customers. They are not only very special amenities – beautiful and delightful recreational spaces to satisfy the soul – but they also have numerous hugely practical benefits such as energy cost reduction, improved air quality, biodiversity, moderation of the heat island effect, storm water control and much more.

Electronic Leak Detection: While hit or miss flood testing had been used for many years for Quality Assurance (QA) the innovation of Electronic Leak Detection (ELD) in the 1990’s was a huge leap forward in integrity testing. It gave us the ability to confidently deliver 100% leak free vegetative roofing assemblies. While each Electronic Leak Detection procedure has advantages and disadvantages in specific situations, all can provide highly accurate Quality Assurance results … when the necessary conditions are present. Low Voltage Electric Field Vector Mapping, High Voltage ELD, the Low Voltage Scanning Platform and the Low Voltage Vertical Roller can all ensure that we are delivering watertight assemblies. However, it is critical to understand that the test procedures require a high-quality electrical ground immediately available under the membrane if thorough and accurate testing is to be provided.

Immediately Accessible Grounds are Paramount: The ELD test procedure can only work when an electrically conductive ground is available to accept the test currents. Structurally reinforced concrete decks are excellent grounds. Thorough and accurate leak detection can be conducted when Inverted Roof Membrane Assemblies (IRMA) roofs are installed directly on these substrates. However, a new challenge emerged when the test techniques were applied to conventional insulated roofing systems. It quickly became clear that inaccurate testing would occur when there were materials like insulation and cover boards between the membrane and the conductive deck. These materials were both thermally insulating and electrically insulating and thus prevented the test currents from reaching the ground and completing the circuit required to locate any breaches.

American Society for Testing and Materials: ASTM has responded to this challenge by issuing two Electronic Leak Detection (ELD) standards that directly address the question of alternative grounds and proper ground positioning to ensure 100% accurate ELD. Both D7877 and D8231 require “placing a conductive material directly under the membrane” when the electrical path to the conductive deck is interrupted. [emphasis added]


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