Mitigation of Radon Gas in Homes

Success Case of Radon0 and ALARA_radon

Sometimes, determining the entry points of radon gas inside buildings, even knowing that it mainly comes from the ground, is not easy.

In this case, we can observe a house built on a slope, whose lowest floor was completely buried by one of its main facades. The other wing of the house remained completely open to the outside, specifically to the rear patio of the plot on which it was built.

Illustration by: Frutos, Borja. Eduardo Torroja Institute (CSIC)

Plan of house exposed to radon gas

In this case, radon gas could penetrate both through the buried side of the lower floor and through the ground in contact with the land.

Actions for radon mitigation are always based on obtaining the best results compatible with the minimum possible intervention. In this case, a phased action was scheduled, starting with the least invasive and continuing with the one that was most affecting the house, but also had the greatest guarantees of success.

A barrier method is applied taking advantage of the fact that the owners wanted to do a small renovation. After careful preparation of the support, including sealing all the cracks and joints in the basement floor, as well as the staircase connecting the two floors of the house, the barrier was applied. This action led to a slight reduction in the levels of radon gas concentration inside the house, not reaching this first remedial measure's goal of bringing this value below the recommended by the World Health Organization (WHO), so it was necessary to implement a second phase.

Radon Gas Mitigation in Homes. Tests and Expert Visit

The testing campaign was intensified, using equipment for continuous measurement and subsequent analysis. The construction typology of the house and its age greatly complicated a clear location of these entry points.

Different mitigation systems were considered, such as the active depressurization of the ground under the house, which was the one that initially obtained the most votes for its use. The difficulties posed by the house itself to implement a duct directly from the subsoil to the roof made its use problematic.

Satisfactory Solution for Radon Gas Mitigation

Finally, the use of a pressurization system was studied. For this purpose, mechanical ventilation was employed with double flow, adapting its design to achieve a slight overpressure in the basement. This radon gas mitigation action, additionally, meant an improvement in indoor air quality for the occupants of the house.

Once the equipment was set in motion, radon levels in the house were monitored again. Thus, the optimal result of the action taken could be confirmed. The second phase resulted in a notable decrease in the concentration of gas in the home, optimizing that concentration towards values below the current reference level. The house currently presents a concentration of radon gas below the value recommended by health authorities.

Complex cases like the one described are resolved satisfactorily by studying the best solution for the client. For this, the most suitable mitigation systems are chosen according to their needs.

Data Obtained in the Last Two Mitigation Executions with Siber Systems

Radon Gas Mitigation - Case 1

MEASUREMENTS PROVIDED BY CLIENT: 350 Bq/m3 (Living room of the house)

LOCATION OF THE RADON INFLUX SOURCE: Sanitary slab

SOLUTION: Active depressurization system of the sanitary slab

RESULT: Final certification after extractor installation: 37 Bq/m3 (Living room of the house)

Radon Gas Mitigation - Case 2

MEASUREMENTS PROVIDED BY CLIENT: Average prior concentration of radon in basement living room of 500Bq/m3

LOCATION OF THE RADON INFLUX SOURCE: Sanitary slab

SOLUTION: Installation of Double Flow System

RESULT: 150 Bq/m3. This last measurement has been taken with a continuous measurement detector; we are waiting for certified measurement using trace detectors.

RADON GAS MITIGATION-Result with measurement-Solutions-Images of cases- ALARA IAQ

ALARA_Radon works in a specific department for radon gas mitigation projects, applying the most suitable techniques for each project.