What you should know about radon decontamination

  • Radon is a radioactive noble gas. You can neither see, smell nor taste it. Radon is a decay product of Uranium and spreads into the air through cracks in the ground. It gets into the house through leaks in pipelines and concrete. However, there are ways to decontaminate it. In this article we answer some questions about radon decontamination.

    Which system does Corroventa use?
    Corroventa’s machines create under pressure in the ground. Usually you have a high pressure in the ground and an under pressure in the crawl space or the basement. This allows radon to enter through cracks and gaps in the concrete or pipes.

    How does the decontamination system work in crawl spaces?
    In crawl spaces you have to combine ventilation and dehumidification. If you only use ventilation you will get problems with moisture and mould in the future as you suck warm, moist air inside the crawl space which cools down and increases the level of humidity. The machine installed will produce under pressure in the ground and prevent the radon from entering the house. You have to make sure that the crawl space is sealed, otherwise the radon will manage to enter the house. When the system has been operating for a while you take radon measurements. If these measurements of radon concentration are still too high you may have to install additional machines.

    How does the decontamination system work in a basement?
    The system is similar to the one used for crawl spaces. You have a high pressure in the ground and a low pressure in the house which allows radon to enter the house. Therefore, you want to produce a lower pressure in the ground. The machine is installed in the basement und sucks the radon from underneath the basement. In this way, the pressure in the ground is reduced and radon does not enter the building. However, you also need to seal all non-surface cracks and gaps in the basement as well as other entry paths at e.g. pipes.

    Which machines are needed for radon decontamination?
    In crawl spaces you use the CTR 300TT2, a dehumidifier which can create a variable negative pressure. Due to the damper solution it can also be used for radon decontamination. The RS100 and the RS400 are used in e.g. normal basements. The RS100 is used for radon decontamination in houses with slabs or basements where material is not very air-permeable. The RS400 is used for houses with slabs or basements where the surface is porous.

    Is sealing the gaps and cracks enough?
    Radon is impossible to decontaminate with a sealing solution in the long run. After a few years, the house can move and cracks will form again making the radon problem reappear. The only good solution for the long-term is to suck the radon from the ground before it enters the building.

    Does the system have to be installed permanently?
    Yes, radon gas is a permanent problem.

    Does radon need to be vented above the roofline?
    The air blown outside has a high radon level. You should not locate the exhaust pipe near an area frequently used by people e.g. a sitting area or near the ventilation system. It is not common to vent radon above the roofline.