Retests After Mitigation
People often mistake the system’s manometer gauge as an indication of the radon levels in the home. Unfortunately, that’s NOT what this is showing: This gauge shows how much pressure is in the system (i.e. how much air the fan is moving), it isn’t a indication of the radon levels at all.
The initial post-mitigation test should be performed by a licensee who will also do a visual inspection of the system to ensure certain components of the system comply with state regulations.
A post-mitigation test is performed in the exact same way as the initial test (assuming the test was done properly and in accordance with state protocols the first time).
It is recommended that all homes be tested every two years. This INCLUDES homes with mitigation systems. As homes age, they change, and mitigation systems sometimes need adjustments to compensate for those changes. That said, after the initial post-mitigation test confirms it is working properly and the design is in compliance with state standards, performing those two-year check-ups can be done with a homeowner test kit (as long as there isn’t a real estate transaction on the horizon.)