Geotextile membrane

Geotextile membrane is a permeable synthetic fabric, normally polypropylene or polyester, used in drainage construction to separate granular materials, prevent fines migration into pipe surround and filter water flow into soakaways. UK installations follow BS EN 13252 and other drainage geotextile standards. The membrane is identifiable by its non-woven felted appearance or woven mesh structure, supplied in rolls and lapped at joints. In Greater London, geotextile is commonly wrapped around soakaway and attenuation crate installations to prevent silt and soil fines clogging the storage void over time. It is also used as a separation layer between drainage gravel and the surrounding subsoil. The material allows water through while retaining particles, significantly extending the service life of the drainage structure. Damage during installation, such as tears from sharp aggregate, can compromise the filter function.