Geomembranes are geosynthetic sheets that ensure the tightness of a surface. They are normally used to remedy water losses due to infiltration or to prevent the migration of contaminants to the soil.

The name geomembrane is subject to the AFNOR NFP 84-500 standard.

Geomembranes are products adapted to civil engineering, thin, continuous, liquid-tight. Currently, products with a functional thickness of less than a millimeter or those whose tightness is ensured solely by the presence of a clay material are not considered geomembranes.

Generally, geomembranes are made of high and low density polyethylene (HDPE, VFPE), bituminous elastomer), polypropylene (PP) or polyvinyl chloride (PVC).

They are generally stored in the form of rollers of different lengths and heights ranging from 1 m by 10 m for bituminous geomembranes to 7.5 m by 200 m for polyethylene geomembranes, for example.

They are used in civil engineering, construction, agriculture, environment and industry.

They are often heat-weldable to make the joints under conditions of optimal quality and reliability.

The most extensive uses are: