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PermaSEAL Self Adhesive Gas Membrane 1m x 20m

£241.50 Ex VAT
£289.80 Inc VAT
Out of stock
Protect structures from water and ground gases with this self-adhesive gas proof membrane.

Gas Resistant Self Adhesive Membranes

PermaSEAL Self Adhesive Gas Membrane is waterproof, self-adhesive and offers reliable protection against ground gases. It is designed for the external/structural waterproofing of foundation walls, basements, external vertical walls as well as flat and ventilated roofs. This self-sealing membrane is the ideal specification when building on contaminated land, providing reliable protection from radon and methane.

This tough waterproofing membrane features a high-density polyethylene film. This innovative film is cross-laminated to provide toughness, continuous protection and stability. A highly adhesive bituminous compound ensures reliable adhesion in all directions, even at low temperatures.

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Uses of PermaSEAL Self Adhesive Gas Membranes

This self-adhesive gas protection membrane can be used in the following scenarios:

  • External basement and cellar waterproofing
  • Waterproofing underground structures / foundations
  • External structural waterproofing
  • External vertical walls
  • Podium decks
  • Flat and ventilated roofs

It is suitable for construction where the ground gases radon and methane are present. PermaSEAL Self Adhesive Gas Membrane is also compatible with various metals including steel.


When it comes to water and gas protection, our PermaSEAL Self-Adhesive gas membranes lead the way. The quality of the bitumen means they are quick to apply and super adhesive. They are tough and self-protecting which means they are resistant to rips and perforations. They are also extensible, which means that they are stretchy in all directions to provide continuous protection. The membranes are resistant to chemical agents.



Start by making sure your substrate is clean, free of dust and previous coatings, smooth and dry. A primer will be required for porous substrates - we recommend PermaSEAL Self-Adhesive Bitumen Primer. Closely follow the instructions to guarantee correct application.


PermaSEAL Self Adhesive Gas Membrane needs to be applied downwards. This means you start with the roll at the highest point and make your way down. Overlap the membrane by a minimum of 50mm on edges and 150mm on top joins.

Once rolled out in position, press the membrane against the substrate. You should pay particular attention to corners, edges and overlaps. Use a pressure roller on all joints and overlaps to seal the membrane and remove any trapped air.

PermaSEAL - Complete Solutions. Made Possible.

When it comes to water and gas protection, you can trust PermaSEAL membranes. Our PermaSEAL range brings together technical excellence and high quality at low trade prices. If you have any questions about external waterproofing or specifications, please give our technical team a call.


  • Tough waterproof and gas-resistant membrane
  • Self-adhesive and self-sealing
  • Protects against radon and methane
  • Compatible with metals
  • Cold-applied so no need for heating
  • Complies with EN 13969, EN 14967
  • Conforms to BS 8102:2022 – Code of practice for protection of below ground structures against water from the ground as a Type A (Barrier) System.
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