There are two approaches to radon mitigation or reduction. One is to prevent the radon from entering the structure and the other is to remove the radon after it enters the structure. Generally, the best approach is to prevent the radon from entering.
Some of the techniques used are soil depressurization, sealing cracks and joints, pressurizing the building, or a combination of these. Sealing foundation joints and cracks is rarely sufficient as a stand alone mitigation technique. Soil depressurization, the most common approach, involves running PVC pipe through the slab (or underneath a membrane in a crawl space), then routing it up and through the roof. A fan is attached in the attic area, and the radon is thus drawn from below the slab (or membrane) and vented above the roof where it is quickly diluted in outside air. Pressurization is fairly difficult to maintain, and is less commonly used as a mitigation approach.
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