The integrity of some assemblies installed to provide the required protection from the ingress of precipitation in vegetative roofing systems can be compromised due to an inadequate resistance to the penetration of plant roots and rhizomes.
Additional information on vegetative roofing systems and the performance of protective materials can be found in the German Landscape Research, Development and Construction Society’s (FLL) “Guideline for the Planning, Execution and Upkeep of Green-Roof Sites” and in the National Roofing Contractors Association’s Vegetative Roof Systems Manual.