If you’re involved in designing or constructing new buildings, chances are you’ve come across the requirement to include radon protection. But why is this important and how can you ensure that it is effective?
Protecting New Homes From High Radon Levels
At the point of construction, steps can be taken to protect a property from future ingress of radon gas. This is most likely to be in the form of a radon barrier (or radon membrane) and may also include the provision of radon sumps.
The Building Regulations require ‘basic’ radon protection to be installed in new properties located in areas where it is estimated that 3% or more properties will be affected by high levels of radon. Basic radon protection involves the installation of a gas-tight barrier (radon membrane) across the entire footprint of the site.
In areas where it is estimated that 10% or more properties will be affected by high levels of radon, ‘full’ protection is required, which involves the installation of a barrier plus either a ventilated subfloor void or the provision of a ‘standby sump’ which can be capped off and activated at a later date if required.
A radon membrane will not provide full protection against radon ingress thus meaning that some properties may have high radon concentration levels above the action level.
Radon testing is advised to be used in the first full year of occupation of the house to give a good indication of where extra radon mitigation measures will be needed. Types of extra radon protection can include adding a radon fan to a radon sump system.
Research recently carried out by Public Health England (PHE) shows that installing radon protection in new buildings reduces the mean indoor radon concentration by over 40% and is, therefore, an important part of the construction process.
Choose Your Materials Carefully
It is important to choose a membrane material that will not only be gasproof but which will be resilient to site conditions. A reinforced membrane that can be heat-sealed is the best choice.
The Devil is in the Detail
Whatever material you choose, it is only as good as the installation. Due to pressure differences between the soil and the building that will ultimately be above the membrane, gas can be drawn through even the smallest imperfections so attention to detail is critical. This means ensuring any joints are fully sealed and that ‘top hats’ are used to seal around service penetrations.
Protect Your Protection
Having gone to the time, and expense, of selecting the best materials and taking the time to install them perfectly, don’t let that effort go to waste by allowing the barrier to be damaged by following trades.
Everyone on site should be informed of the importance of the radon membrane so extreme care can be taken when walking across it and nobody decides to simply cut a hole for a late addition piece of pipework. It is also a good idea to have the installation independently verified at this stage so any faults can be easily rectified.
Futureproof Your Design
Where full radon protection is required and standby sumps are to be installed, pick a sensible place for the pipework to be capped off so that if it needs to be activated in the future, the exhaust pipework and fan can be mounted above. Do not terminate the pipework beneath a window or door threshold.
Have Radon Testing Carried Out
The only way to be sure that the radon protection installed has been effective is to carry out a radon test. The research carried out by PHE revealed that around 10% of properties with basic radon protection still contained radon levels in excess of the ‘action level’ so a new property with inbuilt radon protection should never be assumed to be free from radon.
The test should only be completed once the property is occupied and in normal day-to-day use, as factors such as heating and ventilation will affect the indoor radon level.
The test will show whether any standby sumps need to be activated by adding a radon fan. The purchaser of the property should be given a copy of the test results, along with details of any radon protection installed.
Exposure to radon is the leading cause of lung cancer in non-smokers and is responsible for over 1100 deaths in the UK every year. By ensuring that new properties are effectively protected from radon ingress, we can help to reduce this number.
