How to Mitigate Radon? Protecting Your Home and Health
Radon mitigation involves a multifaceted approach primarily focused on preventing soil gas containing radon from entering a building and safely venting any existing radon outdoors. Active soil depressurization (ASD) is the most effective and widely used method, typically involving the installation of a vent pipe and fan to draw radon from beneath the foundation and exhaust it above the roofline, preventing it from accumulating indoors.
Understanding the Radon Threat
Radon is a colorless, odorless, and tasteless radioactive gas that occurs naturally from the decay of uranium in soil, rock, and water. It’s a significant health hazard, being the second leading cause of lung cancer after smoking and the leading cause of lung cancer among non-smokers. Exposure to radon primarily occurs when it seeps into buildings through cracks and other openings in foundations. The amount of radon in the air is measured in picocuries per liter (pCi/L). The Environmental Protection Agency (EPA) recommends mitigation if radon levels are 4 pCi/L or higher.
Assessing Your Radon Risk: Testing is Key
The first step in mitigating radon is determining whether a problem exists. Radon testing is a relatively simple and inexpensive process.
Types of Radon Tests
There are two main types of radon tests:
- Short-term tests: These tests measure radon levels for 2-7 days and provide a quick indication of the potential risk.
- Long-term tests: These tests measure radon levels for 90 days or more, providing a more accurate assessment of the average radon concentration over time. Long-term tests are recommended to confirm high results from short-term tests.
Testing kits are available at most hardware stores, online retailers, and from state radon offices. Follow the instructions carefully to ensure accurate results.
Active Soil Depressurization: The Gold Standard
Active soil depressurization (ASD) is the most common and effective radon mitigation technique. This system involves the installation of a vent pipe and fan to draw radon from beneath the building’s foundation and exhaust it above the roofline, where it is safely dispersed.
Components of an ASD System
- Collection Point(s): A hole is drilled through the concrete slab or foundation wall to access the soil beneath the building.
- Vent Pipe: A PVC pipe is installed to collect radon gas from the soil and direct it upwards.
- Fan: A specialized radon mitigation fan is installed in the vent pipe to actively draw radon gas from beneath the building. The fan is typically located in the attic or outside the building to minimize noise.
- Exhaust Point: The vent pipe extends above the roofline to safely exhaust radon gas into the atmosphere.
- Manometer: A device that measures the pressure difference in the vent pipe, indicating proper system function.
Installation Process
A qualified radon mitigation professional should perform the installation of an ASD system. The process typically involves:
- Inspection: The contractor will inspect the building to identify potential entry points for radon.
- System Design: The contractor will design an appropriate ASD system based on the building’s construction and radon levels.
- Installation: The contractor will install the vent pipe, fan, and exhaust point.
- Sealing: The contractor will seal any cracks or openings in the foundation to prevent radon from entering the building.
- Testing: After installation, the contractor will perform a post-mitigation test to ensure the system is effectively reducing radon levels.
Other Radon Mitigation Techniques
While ASD is the most common, other techniques can be used depending on the building’s construction and radon levels.
Sub-Slab Depressurization
This method is similar to ASD but involves creating a depressurized zone beneath the entire concrete slab. It’s often used in new construction to proactively prevent radon entry.
Block Wall Depressurization
This technique is used for buildings with hollow block foundation walls. It involves depressurizing the hollow blocks to prevent radon from entering the building.
Sealing Cracks and Openings
Sealing cracks and openings in the foundation can help reduce radon entry, but it is generally not sufficient as a standalone mitigation method. It’s best used in conjunction with other techniques like ASD.
Ventilation
Increasing ventilation in the building can help dilute radon levels, but it is not a reliable mitigation method as it can be energy inefficient and may not effectively reduce radon concentrations.
Positive Pressurization
While less common, this involves using a fan to create positive air pressure inside the building, preventing radon from entering. This method requires careful balancing to avoid moisture problems.
FAQs About Radon Mitigation
Here are some frequently asked questions about radon mitigation to further clarify the process and its implications:
1. What radon level requires mitigation?
The EPA recommends mitigation if radon levels are 4 pCi/L or higher. However, many experts suggest considering mitigation at levels between 2 and 4 pCi/L, especially for families with children or individuals who smoke.
2. How much does radon mitigation cost?
The cost of radon mitigation varies depending on the building’s size, construction, and the chosen mitigation technique. A typical ASD system costs between $800 and $2500.
3. How long does it take to install a radon mitigation system?
The installation of a standard ASD system typically takes one day.
4. Does radon mitigation affect my home’s resale value?
While some buyers might be concerned about a radon issue, having a properly installed and functioning mitigation system can actually increase your home’s resale value. It demonstrates that you’ve addressed the issue and provides peace of mind for potential buyers.
5. How do I choose a radon mitigation contractor?
Choose a certified radon mitigation contractor who is licensed and insured. Ask for references and check their credentials with your state radon office. Look for contractors who are certified by the American Association of Radon Scientists and Technologists (AARST) or the National Radon Proficiency Program (NRPP).
6. How do I know if my radon mitigation system is working?
After installation, a post-mitigation test should be performed to verify that radon levels have been reduced below the EPA action level of 4 pCi/L. Regularly monitor the manometer to ensure the fan is functioning properly. You should also conduct follow-up radon tests every two years to ensure the system continues to be effective.
7. Can I install a radon mitigation system myself?
While DIY radon mitigation kits are available, it is generally not recommended unless you have extensive experience with construction and HVAC systems. Improper installation can be ineffective or even create other problems, such as backdrafting of combustion appliances. Hiring a certified professional ensures the system is installed correctly and safely.
8. Does radon mitigation require permits?
In some jurisdictions, a permit may be required to install a radon mitigation system. Check with your local building department to determine if a permit is necessary.
9. Are there any ongoing maintenance costs for a radon mitigation system?
The primary maintenance cost is the electricity to run the fan, which typically costs a few dollars per month. Radon mitigation fans have a lifespan of about 5-10 years and may need to be replaced periodically.
10. Does radon mitigation work in all types of homes?
Radon mitigation techniques are effective in most types of homes, including houses with basements, slab-on-grade foundations, and crawl spaces. The specific mitigation technique used will depend on the building’s construction and radon levels.
11. What if my neighbor has high radon levels?
Radon levels can vary significantly from house to house, even on the same street. Your neighbor’s radon levels are not indicative of your own. It is essential to test your own home to determine your individual radon risk.
12. Can a radon mitigation system be turned off?
No, a radon mitigation system should not be turned off. The system is designed to continuously reduce radon levels, and turning it off can allow radon to build up inside the building. Leaving the system running ensures continuous protection against radon exposure.
Conclusion: Protecting Your Family’s Health
Radon mitigation is a crucial step in protecting your family’s health from the dangers of radon exposure. By understanding the risks, testing your home, and implementing effective mitigation strategies like active soil depressurization, you can significantly reduce your risk of lung cancer and create a safer living environment. Remember to always consult with a certified radon mitigation professional for accurate assessment and installation to ensure the effectiveness and safety of the system.