The role of materials R&D in protecting homes from radon gas

Radon gas protection is a key requirement in many parts of the world. Jagan Mohanraj, Innovation Director at Visqueen reviews how the challenge of high ground gas levels, low ambient temperatures and demanding regulations were met through an extensive materials R&D programme that has helped develop a radon gas protection barrier for use in other demanding environments.

Risks of Radon

Ask someone what they think is the leading cause of lung cancer and most will respond with smoking and in that they would be correct. But ask those same people what they think the leading cause of lung cancer is in non-smokers and they might not be so sure. In fact, long-term indoor radon gas exposure is the leading cause of lung cancers in non-smokers with over 1,100 cancer deaths attributed to radon in the UK per year.

Radon is a radioactive gas that is formed from the decay of uranium in the earth’s crust. Once formed the gas rises to the surface in minute amounts, too low to be harmful in the open air but over time it can accumulate in buildings. Living in a space with elevated radon levels risks radon particles being inhaled where the radioactivity within the lungs greatly increases the risk of cancer developing.

Despite the risks associated with long-term radon exposure, many people aren’t aware of the danger posed. This isn’t helped by the fact that radon is both colourless and odourless and requires specialist equipment to detect.

Some parts of the world are more prone to radon exposure due to their geology with parts of Scandinavia and Ireland having some of the highest concentrations of indoor radon gas in Europe. Trinity College Dublin estimates that 10% of Ireland’s population are exposed to radon levels that exceed the maximum safe amount. Parts of the UK such as Cornwall, Wales and parts of the Pennines also have elevated levels of radon gas with UK Radon, a part of Public Health England, recommending home-owners test for the gas if they live in radon prone areas.

Ensuring Protection

Protecting houses from radon ground gas is therefore essential in many areas and one method used to protect new buildings are radon barrier membranes. These protect homes by forming an airtight barrier between the ground and the floor of a building and can also incorporate a ventilation system.

Radon barriers need to meet a number of challenges to be able to protect inhabitants of newly built homes, particularly where the incidence of radon is high. Countries such as the UK, Ireland and others have made the installation of radon barriers in new builds compulsory in areas found to have high levels of radon ground gas and have reflected this approach through strict regulations and certification requirements for radon barriers.

With more countries beginning to implement similarly tough requirements for radon protection measures in a wide variety of climates, innovations in radon barrier materials were needed in order to satisfy these demands. Pushing the need to innovate further are the  extreme temperature variations these areas often experience, particularly in winter. Cold temperatures present problems during installation as typical radon barrier membranes can be prone to cracking in the cold which renders their protection ineffective.

The Research & Development Approach

Our technical team undertook a research and development approach to produce a radon barrier with the right material blend that would enable a radon gas barrier to meet the strict certification requirements and ensure buildings were protected in all climates. Thus, an extensive in-house testing regime was carried out which ran trials with membranes composed of different blends of thermoplastics, elastomers and barrier additives.

Tests included measuring impact strength and material flexibility using dynamic mechanical analysis methods on the barrier membranes at an extreme range of temperatures (-30°C to 60°C). The barriers were also subjected to an accelerated six-month aging process using water vapour and UV light exposure to simulate real-world weathering. The challenge was to produce a blend that satisfied these criteria whilst not compromising on its resistance to radon ingress.

This process led to the development of a polymer blend that, when used in a membrane, was resistant to cracking at low temperatures, met the demanding 3rd party requirements in high radon countries and due to the polymer blend had twice the impact strength of typical reinforced radon membranes. This resulted in the launch of the Ultimate RadonBlok 400 & 600 for use in Europe.

A worldwide issue

Indoor radon gas is an issue across many countries and one that other governments are beginning to respond to, in order to protect people whilst at work and home. Innovation in the research methods and the materials used will continue to be essential in order to ensure that any barrier protection meets the challenging requirements of both varying legislation and geographic requirements. By taking the learnings and methodology from the production of this radon barrier, companies will be able to provide the building products and effective solutions that each market demands