House & Home Improvements has been commissioned to build two detached houses with a footprint of 12m x 12m each. However, the site on which the houses are being built has been classed as situated in a Radon affected area.
BRE Regulations state that reasonable precautions should be put in place to avoid danger to health and safety caused by contaminants on or in the ground covered.
The level of risk differs across the country according to local geology. The main source of guidance on the risks and solutions is BRE Report BR 211. It includes maps for determining the need for radon protection, as well as detailed information on construction solutions.
If you are in an area where radon maps indicate that no protection is required – and your SI report confirms this – there is no need to take further action. However, if the maps indicate a radon affected area, it is worth confirming this by requesting a detailed assessment from the British Geological Survey (BGS), which focuses more accurately on your location. This will determine the level of protection required.
Andrew Askham, the developer on site said:
“The site investigation report confirmed that gas protection measures were required here in order to ensure that the housing development is safe for habitation. After assessing the products available we selected Visqueen Radon Membrane because its a proven solution and we wanted a product that we could rely on, first time. The fact that it’s a BBA approved membrane also gave that added peace of mind.”
Visqueen Radon Membrane is a BBA approved membrane that is manufactured from an enhanced blend of polymer films that is suitable for the protection of buildings against the ingress of radon gas. Visqueen Radon Membrane has been independently tested for radon resistance also acts as a damp proof membrane.
Visqueen Radon Membrane can be used in most common floor constructions. It is installed in a similar way to a damp proof membrane, but with much greater attention paid to workmanship and detailing in order to achieve effective sealing at all locations.
For “full” protection, you not only need to provide a radon-proof floor membrane, but also an underfloor depressurisation system. Depressurisation can be achieved by natural or mechanical underfloor ventilation through the subfloor space, or from a radon sump if there is no underfloor space. If you prefer to use an in situ slab in contact with the ground, the slab should be supported on the inner leaf.
The full system consists of;
- Visqueen Radon Jointing System, prevents radon ingress at joints,
- Visqueen Top Hat Units prevents radon ingress at pipe penetrations,
- Visqueen Radon Sumps, where subfloor depressurisation may be required.
Benefits of Visqueen Radon Barrier System:
- BBA approved
- High puncture and tear resistance
- Complies with BRE and CIRIA codes of practice
- Also acts as a damp proof membrane
Complete Radon system checklist
- Visqueen Radon Membrane
- Visqueen Jointing Tape System
- Visqueen Top Hat Units
- Visqueen Detailing Strips
- Visqueen Radon Sump
- Visqueen TreadGUARD1500
Visit our website, www.visqueenbuilding.co.uk for further information.
We have produced a series of useful references which are available to download here:
- NHBC guidance on gas contaminated land requirements
- Visqueen Radon Membrane Datasheet 14/01/2014
- Certificate of Factory Production Control
- BBA Certificate 13/5069
- Radon Membrane Declaration of Performance
- Gas Protection guide
- Installation- Step by Step
- Visqueen’s Guide to CE Marking
- Visqueen’s Easy Guide to BS 8485:2007
- Radon affected areas, England & Wales
- Radon affected areas, Scotland
To receive regular updates on our range of products, subscribe to our blog or follow us on the social networks: