What is Radon?

About Radon Gas

Radon is a naturally occurring radioactive gas emitted from the ground. It is a decay product of uranium, of which minute deposits are found in the rocks and soil beneath the Earth's surface. As a gas, radon travels through pathways in the soil and rocks and is drawn to areas of low pressure by a process called advection. The air pressure inside buildings is usually slightly lower than the pressure in the soil or the air outside, so the gas is actively drawn inside buildings.

Radon can be found anywhere in the country, however it is known to be more prevalent in certain geographic locations. The Health Protection Agency has advised that all properties with basements are at increased risk of radon intrusion*, regardless of location. This is due to the basement having multiple surface areas in contact with the ground through which radon can permeate. In addition, a basement usually represents a large area of low pressure to which radon gas will be attracted.

Long term exposure to radon gas has been linked with lung cancer, and it is estimated that over 2000 people in the UK die each year from lung cancer attributed to radon exposure. It is likely that many of these victims were not aware of the risks of radon and as such had not taken precautions to protect their homes or workplaces from its intrusion. When control measures are introduced, a property can be protected effectively from radon entry, so there is no reason to be fearful of it; rather like waterproofing,

if you know that it may present a problem the sensible approach is to ask a specialist to deal with it rather than ignoring it or attempting to overcome it using DIY techniques.

Radon levels inside a building can be tested using a special passive detector. The detector is a small plastic disk which contains a lens. As air enters the detector, any radon present will make tiny indentations on this lens which can be analysed under a microscope in a laboratory to assess the level of radon present.

When an existing cellar is being converted into a useable basement, it is not appropriate to carry out radon tests prior to the conversion as these will not be representative of the radon levels after conversion.

Altering the heating, ventilation and wall linings will all affect how much radon is drawn into and trapped within a basement, so even if low levels of radon are present in a draughty, unused cellar, once converted the levels may increase significantly.

For this reason, it is recommended that radon be taken into account in all basement conversion or creation schemes. Every ADD Waterproofing installation will include radon testing on completion to ensure that the level of gas within both the basement and ground floor rooms is acceptably low. A certificate will be issued to the client confirming the radon levels.

*HPA Advice on the Limitation of Human Exposure to Radon, July 2010.