Global evaluation of geotextile material performance and applications in green roof systems

Green roofs are increasingly recognized for enhancing urban sustainability by regulating temperature, managing stormwater, and supporting biodiversity. A critical but underexplored component is the geotextile layer, which governs filtration, drainage, and system stability. Historically, geotextiles have evolved from natural fibers to advanced synthetic polymers, with comparative evaluations demonstrating that material choice strongly influences performance. Needle-punched nonwoven geotextiles, for example, achieve permeability values of 1.2–1.5 s− 1 with only 25% long-term flow loss, compared to woven types with 0.12–0.18 s− 1 and higher than 50% flow reduction, highlighting their superior hydraulic efficiency. Synthetic geotextiles composed of polyester and polypropylene exhibit high durability, resistance to degradation, and adaptable physical properties such as thickness and density, making them suitable for applications from separation and filtration to green roof structural reinforcement. Pre-installation testing, including tensile strength, puncture resistance, and permeability, is essential to ensure reliability. Natural fiber geotextiles, particularly coir, offer a sustainable balance of durability and water retention, though scalability and availability limit widespread adoption. International case studies further underscore recycled polymer geotextiles as viable substitutes for conventional synthetics. This review identifies the most optimal geotextiles for sustainable green roofs, offering measurable insights for planners, engineers, and researchers.