Ground Gas Protection Luton
Experts In Solutions For Ground Gas Membrane Verification
UK is experiencing a growing concern about harmful, naturally occurring underground gases and vapours. It is vital that the presence of ground gases and the risks associated with them are assessed and mitigated to protect the structure and its users.
There are two possible sources of gas that could be present on a site: they can be natural or they can be a result from its history.
The naturally occurring gases methane is carbon dioxide, nitrogen, and radon. However, these gases can also be found in soil in elevated concentrations relative with normal atmospheric gasses.
Sites with a history of heavy industrial use, landfills, or spillage of petrol, oil, or solvents can produce dangerous gases such methane and carbon dioxide.
Each of the gases and vapours mentioned above have different properties. Some are asphyxiating, flammable and potentially explosive. Others can be toxic and, over many decades, can cause cancer. They can also react chemically with concrete and plastic building materials, which could affect the structural integrity of the buildings. They can penetrate buildings and other structures both above and below the ground.
These are the types of gases that you will find.
- Radon
- Carbon Dioxide
- Nitrogen
- Methane
- Hydrogen
- Sulphide
- Volatile organic compounds (VOC)
Radon, carbon dioxide and methane gasses, as well as VOCs (Volatile Organic compounds such as hydrocarbons), pose a danger to your health. Therefore, new constructions must use the appropriate materials to keep them out.
A ‘Gas Protection Verification Plan’ independent of CIRIA C735 is required. For gas protection, it is necessary to follow a robust design process and construct the building. Once construction has passed independent verification, handover paperwork should be prepared. This should include any necessary measures during the remaining construction phase, such as to prevent damage and during maintenance and operation.
Expert advice should be sought during the assessment of ground gas data and the risk assessment phase. Below are some important documents to keep in mind and reference:
- BS 8485:2015+A1:2019 - Codes of practice for the design of protective measures for methane and carbon dioxide ground gases for new buildings.
- CIRIA C748:2014 - Guidance on the use of plastic membranes as VOC vapour barriers
- CIRIA C682:2009 - VOC Handbook
- CIRIA C735:2014 - Good practice on testing and verification of protection systems to buildings from hazardous gases
- BS 8102:2009 - Code of practice for protection of below ground structures against water from the ground
BS8485+A1 2019 offers recommendations on ground-gas site characterisation and the selections of solutions to design integral gas protective mechanisms for new buildings. This is done in order to prevent methane and carbon dioxide from entering and maintain a safe interior environment. It offers a process that can be used to demonstrate that risks posed by the potential or actual presence of carbon dioxide and methane have been addressed.
To ensure the installation of your gas protection systems meets CIRIA 735 & BS8485 please call our Luton team
What happens to ground gas?
Why is ground gas becoming a problem?
In the past ground gases where not perceived as a risk to users and the buildings themselves. Due to increasing demand for homes, brownfield sites have seen an increase in development. This is because it is more difficult to find new land to develop. Brownfield can also contain pollutants that can damage the soil or ground.
Because of increased awareness about the dangers, the Environment Agency has created new legislation that is more strict in dealing with ground gas issues. It has been adopted across the country by local authorities.
It is important for you to know that potential risk factors can only been determined by an in-depth ground gas investigation. This must be done by a competent ground gas surveyor.
Assessment of ground gas risk
At the desk stage, ground gas and vapour risks are assessed. Ground investigation or assessment is then done. If ground gas hazards are discovered, measurement with monitoring wells in boreholes will usually be part of the investigations. In existing buildings, diffusion tubes or other static measurement techniques may be used. Monitoring programmes can range from days to months depending on the nature of the risk.
After the investigation is completed, it will be possible to interpret the measurement data and determine whether there is a danger from ground gases.
Protection from below ground gasses
Ground gas protection requires a high level of expertise. The GeoShields Ground Gas experts have the knowledge, experience, and skill to do it.
Ground gas protection is often achieved by ventilation and ground membranes in construction. This provides primary and secondary protection against the ingress of gases. Foundation-based ground gas protection will not work if you are an existing homeowner. Ventilation is essential. Natural ventilation can be used for suspended floors or improved underfloor ventilation. Mechanical ventilation systems can also be used to ventilate the property. This allows harmful ground gases to be controlled and vented safely. In all cases validation of the construction and the installation techniques is important.
There are some situations where gases and vapours may pose risks because they are a byproduct of soil or groundwater contamination. This can be mitigated by remediating the source of contamination.
What are the possible consequences of doing nothing?
It is up to you to decide whether or not you react to the discovery of possible ground gas risks. Some will impact your health, while others could affect the integrity and safety of the building. It has been found that the effects of radon on the human body can cause lung cancer, Carbon Dioxide can be toxic and cause asphyxiation, Methane and Volatile organic compounds (VOC) can be explosive/ flammable. Low levels of Methane (5%) can make it flammable.
The property may be deemed too dangerous for mortgage lenders.
What is Ground Gas Membrane and How Does It Work?
Due to the hazardous nature of ground gasses, buildings should be protected to ensure safety and integrity. Ground gas membranes are usually used to protect buildings.
Ground gas protection membranes are often made of polymers, but may also contain other materials such as aluminium. They are lightweight, flexible, and easily formable. They stop gas from escaping the ground and entering the building.
To ensure the installation of your gas protection systems meets CIRIA 735 & BS8485 please call our Luton team
Other areas near Luton we cover include: