Why Post Mitigation Testing Matters
Installing a radon mitigation system is only half the job. The other half is confirming, through professional testing, that the system is actually reducing radon levels to safe concentrations. Post mitigation testing provides documented proof that your system is performing as designed and that the air in your home is below the EPA action level of 4.0 pCi/L. Without this verification step, you are trusting that the system works based on assumption alone. At Five Seasons Radon, we include a post-installation radon test with every system we install because we believe that measured results are the only results that count. It is also a critical step for real estate transactions, where buyers and lenders often require documented test results showing that mitigation has been successful.
The 48-Hour Post Mitigation Testing Protocol
Our post mitigation testing follows the EPA's recommended protocol for short-term radon measurement. After your mitigation system has been operating for at least 24 hours, we place a continuous radon monitor (CRM) in the lowest livable level of your home, typically the basement or main floor. The monitor runs for a minimum of 48 hours under closed-house conditions, recording radon concentrations on an hourly basis. During this period, all windows and exterior doors should remain closed except for normal entry and exit, and the mitigation system must be running continuously. At the end of the testing period, we retrieve the monitor and generate a detailed report that includes the hourly readings, the 48-hour average, and a pass or fail determination based on the EPA threshold of 4.0 pCi/L.
Included with All Installations
Every radon mitigation system installed by Five Seasons Radon comes with a complimentary post-installation radon test at no additional charge. We schedule the test to begin within 24 to 48 hours after your system is operational, and results are typically available within three business days. If your post-mitigation test shows levels still at or above 4.0 pCi/L, our performance guarantee covers all necessary system adjustments, additional suction points, or fan upgrades required to achieve compliant results. You will not pay a penny more until your home tests below the EPA action level. This guarantee reflects our commitment to your family's safety and our confidence in the systems we design and install.
Beyond the initial post-installation test, we strongly recommend ongoing monitoring of your radon levels. The EPA advises retesting your home every two years, even with an active mitigation system in place, to ensure continued performance. Soil conditions, foundation settling, and changes to your home's HVAC system can all influence radon entry over time. We also recommend testing after any major renovation that disturbs the basement slab or foundation walls. For homeowners who want continuous peace of mind, we can advise on electronic radon monitors that provide real-time readings and alert you immediately if levels rise above a set threshold. Regular testing is the simplest and most reliable way to confirm that your mitigation system continues to protect your family year after year.
What's Included with Our Post Mitigation Testing
- Professional-grade continuous radon monitor (CRM) deployment
- Minimum 48-hour testing under closed-house conditions
- Hourly radon concentration readings throughout the test period
- Detailed written report with average levels and EPA comparison
- Included at no charge with all new system installations
- Performance guarantee if levels remain above 4.0 pCi/L
- Available as a standalone service for existing systems
- Guidance on ongoing monitoring and retest schedules
- Recommendations for continuous electronic radon monitors
- Documentation suitable for real estate transactions
- Licensed and insured technicians