Gas Membranes

The gas membrane installation within buildings is a highly skilled and specialized activity. It is becoming more of a requirement in the construction industry today due to the release of greater amounts of brownfield land.

There are many reasons and conditions that cause gas to be generated naturally underground. The production of underground gases would not normally be an issue as the escaping gases are naturally dissipated into the atmosphere. However, ground gases can infiltrate buildings and build up in areas of poor ventilation - this can create dangerous environments for inhabitants and can be harmful to health.

The most common ground gases to cause issues are:

• Methane:  Forms an explosive mixture in air at levels of 5-16% by volume.
• Carbon Dioxide (CO2):  A toxic, asphyxiating gas; maximum permissible levels 0.5% by volume for long-term exposure, and 1.5% by volume for short-term exposure.
• Radon:   A radioactive gas associated with increased levels of cancer. Radon gas is tasteless and odourless and is highly hazardous for human beings, hence the importance of an effective radon barrier.

Less common hazardous gases could include carbon monoxide, hydrogen sulphide and hydrogen.

To combat these issues, a gas-resistant membrane can be installed in order to seal the footprint and foundations of a building. If the amounts of gas produced are particularly high, then a venting system is required to stop gas pressure build-ups beneath a building and to vent them safely into the atmosphere.

Geo-Barriers gas protection membranes and accessories comply with the latest codes of practice including NHBC Traffic Light System for domestic dwellings, and BS8485:2015 for commercial projects. We can provide technical guidance to ensure that our customers receive the most cost-effective solution, whilst complying with current guidelines.

We are also pleased to be able to offer a fully independent verification and testing service. Our industry leading professionals provide inspection, testing and verification of all major gas membrane and venting installations, and we can organise external verification and testing of our own installations in accordance with C735 requirements.