Plan protection layers and leak-location methods for green roof / plaza deck waterproofing

Steps

1. Confirm the assembly's layer sequence against the membrane manufacturer's approved detail (typically membrane → protection course/board → drainage layer → filter fabric → growing medium or wearing course) rather than a generic layering detail.
2. Flood test the bare membrane per ASTM D5957 before any protection or growing-medium layers are placed, since this is the last point it's fully accessible and repairable.
3. For post-installation or suspected-leak scenarios where the assembly is already covered, use electronic leak detection per ASTM D7877 (Standard Guide for Electronic Methods for Detecting and Locating Leaks in Waterproof Membranes), which describes a low-voltage method (conductive water path to a breach) and a high-voltage arc method — confirm which method suits the specific membrane conductivity and covering condition.
4. Recognize D7877's own stated limitation: it's meant to supplement, not replace, visual or infrared inspection — plan to combine methods rather than rely on electronic scanning alone.
5. Calibrate leak-detection equipment per the manufacturer's procedure and verify sensitivity before and during a survey.