Ground Gas Protection Liverpool
Experts In Solutions For Ground Gas Membrane Verification

UK residents are facing increasing problems from dangerous, naturally occurring below-ground gasses 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.

Natural gasses or historical usage may cause gases to be present at a site.

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 used in the past for landfill, heavy industrial, or where petrol or oil may have leaked can also emit hazardous gases like methane or carbon dioxide.

The gases and vapours listed above can cause cancer if they are not used in sufficient quantities. They may react chemically with concrete or plastic building materials and cause damage to the structure of the building. They can be found in buildings and other structures above and below ground.

There are many types of gas.

 

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.

According to CIRIA C735, a separate ‘Gas safety verification plan’ (or ‘Gas protection verification document’) is required. A robust design and construction process should then be followed to install the gas protection measures and the requirements of ‘verification plan’ implemented. 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.

It is recommended that specialist advice is obtained in the assessment of the ground gas data and at the risk assessment phase. These are the most important documents you need to know and to refer to:

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 provides a method that can be used for demonstrating that there are no risks from the possible or actual presence carbon dioxide and methane.

Contact our Liverpool team for more information on ensuring that the installation of your gas protection systems meets the required legislation & regulations

How does ground gas happen?

Both brownfield and greenfield sites have the potential to develop harmful ground gases from various sources. Some gases are found naturally in the ground and others are caused by human activities such as mining, dumping, landfilling, and mining. These and other human activities have created an environment that allows harmful gases to build up in the ground. The potential for high concentrations in harmful ground gases to pose health risks to people who live near them or are working on their behalf.

Why has ground gas become such a problem

In the past ground gases where not perceived as a risk to users and the buildings themselves. As it is becoming increasingly difficult to find suitable sites for development, there has been an increase in the number of brownfield sites. Brownfield sites may contain contaminants that can affect the ground or soil.

Due to the the increased awareness of the risks the Environment Agency has produced new legislation with a much stricter approach when dealing with potential ground gas issues.This legislation has been adopted by local authorities throughout the country.

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 risks

The risk from ground gases or vapours must be assessed first at the desk stage. If ground gas risks are identified, then borehole measurement will be performed. You can use static measurement techniques and diffusion tubes in buildings. Depending on the nature and severity of the risk, monitoring programmes can last from days to months.

After the investigation is completed, the interpretation and assessment of the measurement data will determine if there is any risk from ground gases or vapours.

Protection from below-ground gasses

Ground gas protection is an extremely specialised operation. GeoShields Ground Gas specialists have the required knowledge, experience and skill levels.

Ventilation and ground gas membranes are used to mitigate the effects of harmful ground gases. They provide both primary and secondary protection for buildings against the ingress and vapours. A foundation-based ground gas protection system is unlikely to be practical if you’re already a homeowner. Ventilation is therefore the most important factor. Ventilation can use a combination of natural ventilation for suspended floors, improved underfloor ventilation and the introduction of mechanical ventilation systems so that the harmful ground gases can be safely controlled and vented away from the property. In every case, validation of the construction methods and their installation is necessary.

Sometimes, the gas and vapours can pose a risk because they are a result of soil or groundwater contamination. In these cases, remediation may be possible.

What's the impact of not doing something?

The impact of not responding to the potential ground-gas risk depends on the type and extent of the ground gas. Some ground gases can affect your health, others may cause damage to the building’s integrity. There have been studies that radon may cause lung cancer. Carbon Dioxide is toxic and can cause asphyxiation. Methane or volatile organic compounds can also be explosive and flammable. As low as 5% can make methane flammable.

The property may be deemed too dangerous for mortgage lenders.

What is Ground Gas Membrane, exactly?

Ground gases are dangerous and buildings need to be protected. This protects the structure’s integrity as well as anyone inside it. Protection is usually in the for of a ground gas membrane.

Ground gas protection membranes are usually constructed from polymers but also include other materials such as aluminium. This allows them to be lightweight, flexible and formable. They can stop gas from getting into buildings and the ground.

Contact our Liverpool team for more information on ensuring that the installation of your gas protection systems meets the required legislation & regulations