FLAGON® BSL is a synthetic membrane of plasticised PVC manufactured by coextrusion which enables the production of a single layer membrane, each of the two surfaces being a different colour.


FLAGON® BSL is a two-coloured geomembrane used as a waterproofing layer in civil engineering and building structures, such as:
- Tunnels and bored galleries
- Cut and cover tunnels
- Coverings of buried structures
- Underground car parks
- Sealed encasings of civil engineering structures and buildings

FLAGON® BSL waterproofing membrane includes a thin coloured layer or "signal layer" on the visible side of the membrane which allows any damage to be immediately identified and repaired. FLAGON® BSL geomembrane can be used as part of a single-layer waterproofing system, compartmentalised or not, or a Flag Vacuum system.


- signal layer,
- high mechanical resistance,
- resistance to wash-out waters action,
- resistance to roots,
- resistance to low temperatures,
- resistance to eddy currents,
- resistance to bursting.


  • Thickness: 2,0 mm or 3,0 mm
  • Width: 2,10 m
  • Length: 20 m
  • Colour: light green black  


FLAGON® BSL geomembranes are produced by the FLAG Spa factory (SOPREMA group) in Chignolo d'Isola (Italy) and are CE marked in accordance with EN13491, certificate no. 1085-CPD-0012.

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