How to control radon at home or at work. What are your options?

Several means exist to reduce radon. Improving ventilation and sealing floors and walls can reduce the presence of radon by up to 50% and these simple changes are generally suitable for controlling low levels.

Under-floor extract, mini-sumps and positive pressure ventilation systems provide the best solutions. In terms of effectiveness, under-floor extract and mini sumps can reduce radon by 90% while positive pressure ventilation systems decrease it by 50 to 60%.

Under-floor extract and radon mini sumps work by creating lower pressure below floor level which reduces the ingress of radon gas into the building. This system uses an electrically powered radon sump fan that sucks the gas from underneath the floor of a house, either from an existing void under the floor or a new mini sump, and vents it into the atmosphere through a pipe. Developed primarily for houses with solid floors, radon sump pumps can be used in houses with suspended floors depending on the construction of the floor and existing airbricks. Sump fans can be installed externally or internally.

Airflow under suspended floors also can be increased by installing vents. This method has been proven effective on radon levels of up to 700 Bq m3 and in some cases and can be improved by adding fans to create greater movement of air.

Positive pressure ventilation systems can also be used to reduce radon levels. These draw radon free air from the loft space, or directly from outside, via ventilation units installed in the loft space in a house, or on an internal wall in a flat, and silently introduce fresh air throughout the home thereby reducing radon levels. These systems are effective for up to 500 Bq m3 levels of contamination and work better in sealed environments. They have the additional benefit of reducing condensation problems.

Most new houses incorporate preventative measures that control radon and advice on appropriate action to minimise radon is often available from local councils in conjunction with the BRE (Building Research Establishment).

Airtech positive pressure loft unit

Damp proof membranes can be used underground to protect against the ingress of radon gas. These can provide an effective barrier for sealing cavities at ground level. Flexible and compatible with other materials, they retain their physical properties for many years. Preformed shapes are also available to suit pipe penetrations and cavity trays.