Adhesive Gas Membrane

Key features

  • Cold applied membrane
  • High puncture resistance
  • Impervious to radon gas
  • Self adhesive
  • Low vapour transmission
  • Low methane permeability


Cut to size, remove backing paper, apply to substrate. Where applying to a friable surface the application of Keyflex primer is required. Apply by brush or roller, ensure primer is dry before fixing membrane to surface. For detailed application, contact our technical support staff.

Suggested specification

The adhesive gas membrane, Keyflex AGM, must be applied to the substrate with 150mm overlap and contains the minimum gas transmission properties of < 0.03 ml / m² /24h @ atm and where masonry is friable, the substrate shall be primed with Keyflex primer.


Aluminium foil reinforced bitumen rubber compound sheet, with biaxually-oriented HDPE film to one side.


A solution of bitumen in a blend of aromatic and aliphatic hydrocarbon solvents (OEL 100ppm 8 hrs TWA). Coverage rate 5 to 7 m² per litre, less on more porous substrates.

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An integrity testing service is available for all installations on request and third party accreditation
Product specification CE MARK to EN 13967
Size1.05m x 28.6m per roll
Methane transmission< 0.03ml / m² / 24h
Puncture resistance250N ASTM E154
Weight1.2 Kg / m²
Water vapour transmission< 0.1 g / m² / 24h ASTM E96
Radon diffusion coefficient5.0 10-14 m /² s NRPB