How Do You Fix Radon?

Radon mitigation is the process of reducing radon levels in a building, primarily through subslab depressurization. This involves creating a vacuum beneath the concrete slab of a basement or foundation to draw radon gas away and vent it safely outside before it enters the living space.

Understanding the Radon Problem

Radon is a naturally occurring, invisible, odorless, and tasteless radioactive gas produced by the decay of uranium in soil, rock, and water. It can seep into homes and buildings through cracks in foundations, gaps around pipes, and other openings. Long-term exposure to elevated radon levels significantly increases the risk of lung cancer, making radon mitigation crucial for protecting public health. The EPA recommends taking action to mitigate radon levels at or above 4 pCi/L (picocuries per liter).

The Main Solution: Subslab Depressurization

How Subslab Depressurization Works

The most common and effective method for reducing radon levels is subslab depressurization (SSD). This system works by creating a negative pressure zone beneath the concrete slab.

1. Drilling and Excavation: A small hole is drilled through the concrete slab, typically in a basement or crawl space.
2. Creating a Suction Point: Material is excavated beneath the slab to create a small pocket of open space.
3. Installing a PVC Pipe: A PVC pipe is inserted into the hole, connecting the subslab pocket to a fan located either inside or outside the building.
4. Fan Installation and Venting: The fan draws air from beneath the slab, creating a vacuum. This negative pressure prevents radon from entering the building. The radon-laden air is then vented above the roofline, where it is safely dispersed into the atmosphere.
5. Sealing Cracks and Openings: Important to maximize the efficiency of the SSD system, all visible cracks and openings in the foundation and around pipes are sealed with caulk or other appropriate materials.

Types of Subslab Depressurization Systems

There are variations of SSD systems depending on the building’s construction and radon levels:

• Active Subslab Depressurization: This is the most common type, using a continuously running fan to create the negative pressure.
• Passive Subslab Depressurization: This relies on natural air currents and thermal differences to create a draft, without a fan. It’s less effective for high radon levels but may be suitable for new construction.
• Submembrane Depressurization: This is used in crawl spaces with exposed earth. A durable plastic membrane covers the ground, and a fan draws air from beneath the membrane.

Choosing a Radon Mitigation Professional

While DIY radon test kits are readily available, radon mitigation is best left to qualified professionals. A certified radon mitigation specialist will:

• Conduct thorough testing to determine the radon levels.
• Assess the building’s construction and identify potential entry points.
• Design and install the most effective mitigation system.
• Ensure the system meets all applicable codes and regulations.
• Provide post-mitigation testing to verify the system’s effectiveness.

Other Radon Mitigation Techniques

While subslab depressurization is the primary method, other techniques can be used in specific situations:

• Block Wall Depressurization: Similar to subslab depressurization, this involves drawing air from within hollow concrete block walls.
• Drain Tile Depressurization: If a building has a drain tile system around the foundation, it can be used to vent radon.
• Radon-Resistant New Construction: In new construction, radon-resistant features can be incorporated into the building design, such as a vapor barrier, a gravel layer under the slab, and a passive vent pipe.
• Sealing: While sealing cracks and openings alone is rarely sufficient to lower radon levels to acceptable levels, it can improve the effectiveness of other mitigation methods.
• House Pressurization: This involves using a fan to create positive pressure inside the house, which can prevent radon from entering. However, it’s often less effective and can increase energy costs.
• Natural Ventilation: Increasing natural ventilation can lower radon levels, but it may not be practical in all climates or during certain times of the year.

Maintaining Your Radon Mitigation System

Once a radon mitigation system is installed, it’s important to maintain it properly to ensure its continued effectiveness:

• Monitor the Manometer: Most SSD systems have a manometer, a simple gauge that indicates the fan is working properly. Check it regularly.
• Listen for Fan Noise: Be aware of any unusual noises from the fan, which could indicate a problem.
• Retest Periodically: It’s recommended to retest radon levels every two years to ensure the system is still working effectively.
• Inspect and Maintain the Fan: The fan may need to be replaced periodically, typically every 5-10 years.

Frequently Asked Questions (FAQs) About Radon Mitigation

FAQ 1: What are the health risks associated with radon exposure?

Radon is a known carcinogen and the second leading cause of lung cancer in the United States, after smoking. The risk is even higher for smokers exposed to radon. Long-term exposure, even at relatively low levels, can significantly increase the risk of developing lung cancer.

FAQ 2: How do I test my home for radon?

Radon test kits are available at most hardware stores and online. You can also hire a certified radon tester. The test involves placing a collection device in the lowest level of your home for a specific period, usually 2-7 days. Afterward, you send the device to a lab for analysis.

FAQ 3: What is considered a safe level of radon?

The EPA recommends taking action to mitigate radon levels at or above 4 pCi/L (picocuries per liter). While there is no truly “safe” level of radon, the goal of mitigation is to reduce levels as low as reasonably achievable.

FAQ 4: How much does radon mitigation cost?

The cost of radon mitigation typically ranges from $800 to $2500, depending on the type of system required, the size and construction of the building, and the local market.

FAQ 5: Will a radon mitigation system affect my home’s energy efficiency?

A properly installed and maintained radon mitigation system should have a minimal impact on energy efficiency. The fan typically uses very little electricity. Sealing cracks and openings can actually improve energy efficiency.

FAQ 6: How long does it take to install a radon mitigation system?

The installation of a typical subslab depressurization system usually takes one day.

FAQ 7: Will a radon mitigation system eliminate radon completely?

While a radon mitigation system can significantly reduce radon levels, it may not eliminate it entirely. The goal is to reduce levels below the EPA action level of 4 pCi/L.

FAQ 8: Does radon affect water?

Yes, radon can be present in well water. If your home uses well water, you should have it tested for radon. Radon in water is typically addressed with an aeration system installed near the point of entry.

FAQ 9: Can radon levels fluctuate over time?

Yes, radon levels can fluctuate due to changes in weather, soil moisture, and ventilation. This is why it’s important to test periodically.

FAQ 10: Are there any regulations regarding radon mitigation?

Some states and local jurisdictions have regulations regarding radon testing and mitigation. Check with your local health department or building codes department for more information.

FAQ 11: What are the signs that my radon mitigation system is not working properly?

Signs of a malfunctioning radon mitigation system include:

• A broken or non-functioning fan
• A reading of zero on the manometer
• Increasing radon levels detected through retesting
• Unusual noises from the fan

FAQ 12: Can I sell my home if it has high radon levels?

Yes, you can sell your home if it has high radon levels. However, you are typically required to disclose this information to potential buyers. Many buyers will request that the seller mitigate the radon before closing.