Where geotextile is used
- Over the geomembrane as a protection layer before cover or drainage material is placed
- Under the geomembrane where the subgrade needs a cushion
- In landfill Categories 1 and 2, where MWAN's guidelines call for a protection layer of geotextile and/or fine sand over the geomembrane
Selecting the grade
The geotextile grade, or the sand thickness where sand is used, is set by analysis or testing for each project, based on the cover material and the loads the liner will carry.
Sequencing with the liner
Protection geotextile goes down only after the geomembrane seams have been tested and any repairs completed and retested. Where the scope includes earthworks, subgrade or cement-stabilised sand cover, our partner civil contractor delivers the civil scope.