Which practice is most likely to enhance the effectiveness of a radon mitigation system?

Regular maintenance checks are vital for ensuring the long-term functionality and efficiency of a radon mitigation system. Such checks typically involve inspecting for any issues that might have arisen since installation, ensuring that all components are operating as intended, and making adjustments as necessary to optimize performance.

Routine maintenance can help to identify and rectify problems such as fan malfunctions, blockages in vent piping, or changes in the building’s foundation or structure that may affect the system’s effectiveness. By regularly maintaining the system, homeowners can ensure that radon levels remain low, thus providing ongoing protection from radon exposure.

In contrast, installing a second radon system may not necessarily guarantee improved performance unless the first system is also well-maintained. Decorative barriers usually serve no functional purpose in radon mitigation; they may even impede airflow or access, which can detract from the system's effectiveness. Lastly, restricting air exchange with the outside can potentially lead to indoor air quality issues and isn't a recommended practice for radon mitigation, as proper ventilation helps manage radon levels effectively in conjunction with active systems.