Radon is a health risk that often goes unnoticed. You can’t see it, smell it, or taste it, but long-term exposure can be dangerous. Many homes in North Carolina and across the U.S. have elevated radon levels without the owners even knowing.
This guide explains where radon comes from, how it enters your home, and what you can do to stay safe. If you’ve never had a test or don’t know how it works, this is a smart place to start.
What Radon Is and Why It’s a Problem
Radon is a naturally occurring radioactive gas. It forms when uranium in soil, rock, or groundwater breaks down. As it decays, it releases gas, which moves up through the ground and into the air.
Outdoors, levels are low and not a concern. Indoors, however, radon can build up to unsafe levels. The U.S. Environmental Protection Agency (EPA) reports that radon is the second leading cause of lung cancer.
It’s responsible for thousands of deaths each year, especially in homes where radon goes undetected for long periods. The only way to know your home’s radon level is to test it.
Where Radon Comes From
The gas comes from uranium found in small amounts in most soils and rocks. When uranium decays underground, it turns into radium. Radium then breaks down into radon gas. That gas escapes from the soil and begins moving upward.
The movement of radon depends on several factors:
- Soil composition: Loose, sandy soil allows gas to move more freely than clay.
- Moisture levels: Wet or saturated soil can slow the flow of gas.
- Rock type: Some rocks, like granite and shale, contain more uranium than others.
These natural conditions vary by location. That’s why one home might have high radon levels while a neighboring home does not.
How It Gets Into Homes
Once radon gas rises through the soil, it can enter buildings through small gaps and openings. Common entry points include:
- Cracks in the foundation or basement floor
- Spaces around pipes and utility lines
- Floor drains and sump pump pits
- Construction joints and wall seams
- Crawl spaces with bare soil
Homes create a pressure difference between indoor and outdoor air. Warm air rises and escapes through the roof, pulling cooler air (and radon gas) from the ground into the home. This “vacuum effect” is strongest in winter when homes are sealed tight.
The gas tends to concentrate in basements, crawl spaces, or lower floors. Over time, if the home is not ventilated or treated, radon levels can rise well above the EPA’s recommended action level.
Does It Affect New Homes, Too?
Yes. Radon is not just a problem for older homes. In fact, newer homes may be more prone to high radon levels because they are built to be energy efficient. Tight construction can limit airflow and make it harder for it to escape.
The size or age of your home doesn’t determine your risk. It all comes down to the conditions beneath your house and how easily radon can travel inside.
Why Seasonal Changes Matter
Levels often change with the seasons. In winter, windows stay closed and ventilation decreases, allowing more gas to collect indoors. Snow cover or frozen soil can trap radon below the surface, increasing pressure and forcing more of it into the home.
Rain, barometric pressure, and wind also affect how radon moves. Because of these changes, short-term tests might not show the full picture. Long-term testing can provide a more accurate view of your average exposure.
What Testing Involves
Radon testing is simple and affordable. The most accurate method is a continuous monitor placed in the lowest livable area of your home for 2 to 4 days. These monitors track hourly levels and calculate an average at the end of the test.
The EPA recommends action if your result is 4.0 picocuries per liter (pCi/L) or higher. Even levels between 2.0 and 4.0 pCi/L are considered risky, especially for long-term exposure.
You can also use long-term tests that run for 90 days or more, which provide better year-round data. DIY kits are available, but for the most accurate results, a professional radon test is the way to go.
How Radon Testing Fits Into a Home Inspection
If you’re buying or selling a home, testing can be included in a standard home inspection. For buyers, it’s important to know the indoor level before closing. If levels are high, mitigation can become part of the negotiations.
For sellers, testing in advance gives you time to fix the issue or show that your home has already been tested and treated. AHI offers testing as part of both residential and commercial inspections throughout the Charlotte area.
What to Do If Levels Are High
If your test results come back high, a radon mitigation system should be installed. These systems usually involve:
- Sealing cracks and openings in the foundation
- Adding a vent pipe to pull the gas from beneath the home
- Using a fan to push the gas safely outside
A typical mitigation system can reduce radon levels by up to 99%. The system runs continuously and often requires little maintenance after installation. In some cases, crawl spaces may need to be sealed or covered with plastic sheeting.
Other Related Questions
Is radon a problem in North Carolina?
Yes. Many counties in North Carolina, including areas around Charlotte, are classified as moderate or high risk by the EPA.
Can I live in a house with radon?
Yes, but only if mitigation is in place. Many homes have radon systems and are completely safe to live in once the issue is addressed.
How often should I test for radon?
You should test every 2 to 5 years, or any time you move, renovate, or make changes to your HVAC or foundation.
Do homes with basements have more radon?
Basements often show higher levels, but it can affect homes with crawl spaces or slab foundations, too.
When to Call a Professional
If you’ve never tested your home, or if it’s been several years since your last test, now is the time. Whether you’re buying a new property, preparing to sell, or just want peace of mind, a professional test is the most reliable way to know your risk.
AHI Residential and Commercial Inspections offers testing as a standalone service or as part of a full inspection package. Our team is trained, certified, and ready to help you make safe, informed decisions about your home.
Conclusion
This gas can be dangerous, but it’s also manageable. Understanding where it comes from and how it enters your home is the first step. Testing is quick and affordable, and mitigation systems are highly effective.
If you’re ready to schedule a radon test or want to learn more, AHI Residential and Commercial Inspections is here to help. Reach out today to book your appointment or ask questions about radon safety in your area.