Separation is the basic use of geotextiles and is widely practised in road works and railway constructions.
The separation function is defined as "The preventing from intermixing of adjacent dissimilar soils and/or fill
materials by the use of a geotextile".

The durability and mechanical properties of Hipertex® Geotextiles make them ideal as separating layers. A strong and flexible geotextile is placed between different layers in the construction, preventing migration and mixing of materials, yet allowing free movement of water. This increases the bearing capacity of the construction and provides long term stability of the foundation layers. The tensile strength, puncture resistance and elongation properties of the geotextile have to be sufficient not only to fulfil the requirements of a separator but also to resist damage during installation.