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Radbar Amber 2 Foil Gas Barrier Membrane 2m x 50m

£495.00 Ex VAT
£594.00 Inc VAT

Protect buildings and their occupants from radon, carbon dioxide and methane gases as well as water ingress with this foil gas-resistant floor membrane. It’s designed to go above and below concrete slabs.

Gas Barrier Foil Membrane

Radbar Amber 2 Foil Barrier Membrane is a low-density polythene gas barrier and damp proofing membrane. It is designed for use in concrete ground floors, both above and below the slab. 

This multilayer membrane features an integral aluminium foil. The foil membrane protects properties and occupants from the ingress of more gases than the standard Amber 1 Membrane including radon, carbon dioxide and methane gases from the ground as well as moisture. It is only suitable when not subject to hydrostatic pressure.

Installing a foil gas membrane

The Amber 2 foil gas membrane is designed for ease of installation. It can be installed by a competent general builder or a contractor that is experienced with gas membranes.


Ensure that the surface has a smooth finish with no projections or voids - this applies to both concrete slabs and brick and blockwork. The surface should also be free from dust and debris and dry. 


Roll out the foil barrier membrane, making sure it is aligned with the surface. The white side should be down with the coloured surface uppermost. 


Where overlaps are required both at ends and along sides, ensure that the membranes overlap by a minimum of 100mm. Where they overlap make sure they are dirt, dust and moisture-free. These joints can then be bonded together with Radbar Double-sided Jointing Tape and sealed with Radbar Single-sided Tape.

The membrane should be covered by a screed or other protective layer as soon as possible after installation. If blockwork protection is used, care must be taken to avoid damage to the membrane during construction.

If going around any pipe work, you can use Radbar Top Hats and correctly sealed.

If you wish to install underfloor heating, this will not impact the membrane.

Read our guide to installing gas membranes.

The membrane should be covered by a screed or other protective layer as soon as possible after installation.

Important note: The membrane installation should be subject to third-party independent validation, in accordance with BS 8485: 2015. Do not install the membrane below 4°C to prevent the risk of surface condensation.

The Radbar Radon System

The Radbar System is a high quality radon system protecting properties from ground gases. It consists of a membrane like the Amber 1 that extends the whole of the floor and walls.

In new build projects, the system will sometimes have an underfloor ventilated sump or sumps installed in areas affected by gas. This can be subsequently converted to an active system by use of suitable ventilation fans if test results require it. Radon sumps can also be installed in existing buildings providing the design of the structure allows it.

Related gas membrane products:

  • Radbar Double-sided Jointing Tape — for joints and lap
  • Radbar Single-sided Overlap Tape.
  • Radbar Top Hat Unit — to seal service entry points to the membrane
  • Radbar gas sump — underfloor ventilated sump
  • Radbar preformed corner details and cloaks — prefabricated details

Permagard - Providing Solutions. Inspiring Confidence.

If you have any questions about gas membranes and how to install radon foil membranes contact our experts. We provide free technical advice on 0117 982 3282.


  • BBA-approved foil barrier gas-resistant membrane
  • Resistant to water & water vapour from the ground - methane, CO2 and radon gas
  • Resistant to underground gases from the ground
  • High resistance to puncture
  • Durable - the foil barrier membrane will remain effective against water and ground gas ingress during the lifetime of the flooring construction in which it is installed