APPEARANCES CAN BE DECEIVING
Some buildings are a slam dunk - a floor slab built on large diameter gravel with no interior footings and a small intrusion pressure. In these situations, a small wattage radon fan may be able to reduce the radon to approximately outdoor levels.
Other buildings are not so straightforward. Crawl spaces are always a challenge, in particular when they are open floor and not readily accessible. Even apparently straightforward buildings might require technical assessment and creativity. Recently we completed an installation at an 1,100 square foot bungalow. The building was of contemporary construction with a basement floor slab on gravel. This should have been a job for a single suction point and small wattage radon fan. But, the configuration of the foundation’s footings and the footing for the stairs meant that the sub-slab was divided into two compartments. A dual suction point system was required to address the entire floor slab.
Looks can be deceiving. Diagnostic testing is key to determining the complexity of the mitigation system that will be required.