We offer a professional mitigation and testing service and recommend that radon reduction work be carried out by those trained in its application. We further recommend that testing be conducted on completion to determine reductions obtained. Radon mitigation work by the untrained has on occasion increased rather than decreased radon concentrations.

1) Exclude soil gas entry (and radon) by means of an impermeable barrier. (This is usually only practical in new construction where it forms the primary measure under part C of the Building Regulations for designated affected areas.)

2) Increase ventilation rates so that the same level of gas is diluted with a larger quantity of air.

3) Positively pressurise the building so that natural building suction is neutralised or at least reduced together with the increase of ventilation rate as above. (Supply only ventilation).

4) Apply (2) above to the void space under a suspended ground floor as either passive or fan assisted (active) ventilation.

5) Reduce the pressure in the soil under the building, either by use of an extraction fan (active system) or using the heat of the house to create a suction in the extraction pipework (passive measure), so that the radon bearing soil gasses can be attracted to a collection point and ducted away to a safe dispersal point in the outside air.

In part C of the Building Regulations, this method is provided for as the ‘secondary’ measure. It consists of chambers or ‘sumps’ under the floor slab of new construction, connected by means of pipework to either an above roof level dispersal point or terminated above ground level outside as a standby future extraction point, capped to exclude vermin. If required, further pipework can be added later, together with a fan, and the system made active.

6) In a few cases the water supply may be contributing to the radon levels and may require attention. The Cornwall Radon Gas Centre can advise where this may be of concern.