What triggers the need for re-testing radon levels?

The need for re-testing radon levels is primarily triggered by altering or modifying a mitigation system. Mitigation systems are installed specifically to reduce elevated radon levels in a home or building. When changes are made to how these systems operate—such as modifications to the fan, changes in the ducting, or adjustments in the sealing—there is potential for the effectiveness of the system to be impacted. As a result, re-testing is essential to ensure that radon levels remain safe after these modifications.

Renovating living spaces, changes to roofing materials, or switching water sources do not directly affect the mechanisms that control radon levels as significantly as modifications to the mitigation system do. Therefore, they do not typically necessitate immediate re-testing. However, changes to a mitigation system warrant re-evaluation of radon presence to ensure ongoing safety and compliance with health standards.