Reducing Dangerous Levels of Radon Gas
When it is determined that a house has unsafe levels of radon gas, what options are available for radon mitigation? How can this poison radon gas be safely removed from the house?
The radon mitigation options appropriate for a house depend on the construction type of the house. Houses with basements, slabs, or crawl-spaces may require different techniques. For houses with basements or slabs, the most common technique for radon remediation is active subslab suction which may also be called subslab depressurization. This approach places one or more suction pipes through the slab into the material underneath the house. These pipes are then connected to a fan that draws the radon gas through the pipes and vent it above the house where it is safely dispersed.
There are other variants of this approach available as well. These variations use existing features of the house to connect to the suction pipes and provide for radon evacuation. Options include using existing perforated pipes or drain tiles around the foundation of the house, using a sump-pump hole, or using the space inside of the foundation walls found in block-wall foundations to remove the radon.
For houses with crawl-spaces, a similar technique for radon remediation is available. This approach, called submembrane suction, places a plastic sheet in the crawl-space directly above the ground and then uses a suction pipe and fan to draw the radon out from underneath the plastic and vent it to the outside. It is possible to attempt this without the plastic sheet, but it is less effective and may cause other airflow issues in the house, including increased energy costs.
Other radon mitigation techniques are available, but should be in conjunction with one of the other techniques listed above. These techniques include sealing, positive pressurization, and improved ventilation within the house. Each of these, however, has weaknesses. For example, it is difficult to ensure all cracks are sealed and that new cracks do not appear and improved ventilation may be impacted by weather and is likely to increase energy costs within the home.
Regardless of the method used for radon mitigation in a home, it is important to ensure that a properly qualified contractor to perform the work. Many states license or certify contractors for radon remediation and you should ask for references before selecting a contractor.