Radon is invisible and odorless, so it is easy to overlook until it shows up on a test. If you live in Cary or are planning a move here, understanding when to test, why it matters, and what to do with the results can protect your health and keep your transaction on track. In this guide, you’ll get local steps, reliable resources, and clear answers for buyers, sellers, and homeowners. Let’s dive in.
Why radon testing matters in Cary
Radon is a naturally occurring radioactive gas that can build up indoors and raise your risk of lung cancer over time. Testing is the only way to know your level. The CDC explains the health risks and why every home should be tested, regardless of age or type (CDC radon testing overview).
North Carolina’s Radon Program estimates about 450 radon-related deaths each year statewide and encourages testing across all counties, including Wake County and Cary. You can find state guidance, county maps, and local resources on the North Carolina Radon Program page.
When to test in Cary
During a home purchase or sale
Test during due diligence so you can confirm levels and plan next steps if needed. The EPA advises buyers to request a new test if the last test is not recent or if proper protocols were not followed (EPA retesting guidance). North Carolina also provides a practical Buyers and Sellers Guide to Radon with transaction checklists.
Sellers and brokers must disclose known material facts. North Carolina’s disclosure law covers hazardous substances, which includes known dangerous radon levels (NC disclosure statute).
After changes or renovations
Test if you finish or start using a lower level, change ventilation or combustion appliances, or make major renovations. The EPA also recommends retesting after significant changes in use or occupancy (EPA retesting guidance).
Season and test conditions
You can test any time of year if you can keep “closed-house” conditions. Short-term tests require windows and exterior doors closed for at least 12 hours before and during the test for tests under one week. Levels often run higher during cooler months when homes stay closed more tightly (short-term testing instructions).
How to test your home
Short term vs long term
Short-term tests run from 2 to 90 days and give quick results. Long-term tests run over 90 days and provide a better read on your yearly average. Both are valid, and the choice depends on your timing and goals (EPA Citizen’s Guide to Radon).
DIY or professional help
For a quick homeowner screen, DIY kits work. In a real estate deal or when you need defensible documentation, consider hiring a certified measurement professional who uses a continuous radon monitor and provides a written report. The state recommends choosing pros certified by national programs like NRPP or NRSB (NC testing guidance and certification info).
Where to get test kits
The North Carolina Radon Program offers discounted or occasional free kits during Radon Action Month and links to certified professionals and local resources (NC Radon Program). If you use a private well, Wake County offers well-water packages that can include radon testing so you can evaluate water and air together (Wake County well-water testing).
What your results mean
The EPA recommends fixing homes at or above 4.0 pCi/L and considering action for 2.0 to 4.0 pCi/L, since there is no known safe level. If a short-term result is 4.0 pCi/L or higher, follow up with a long-term test or a second short-term test. If the average of two short-term tests or a long-term result is 4.0 pCi/L or higher, plan mitigation (EPA Citizen’s Guide to Radon).
Private wells and water
If your home uses a private well and an air test is elevated, test your well water for radon too. As a rough guide, about 10,000 pCi/L of radon in water can contribute about 1 pCi/L to indoor air, and state materials note considering treatment above 4,000 pCi/L. Coordinate air and water testing with your county and state resources (CDC radon basics; Wake County well-water testing).
Fixing elevated radon
Common mitigation methods
Most Cary homes with elevated levels can be fixed with a sub-slab depressurization system that draws soil gas from beneath the foundation and vents it above the roofline. Other methods exist for crawl spaces and block walls. These systems can reduce levels significantly when designed and installed correctly (EPA mitigation overview).
Cost, timing, verification
Many North Carolina homes can be mitigated for about the cost of common home repairs. Typical installations are often completed in a day or a few days, and many projects fall around 1,000 to 2,500 dollars depending on home type and routing. Always verify performance with a post-installation test no sooner than 24 hours and within 30 days after activation, then retest periodically per state and EPA guidance (NC radon mitigation guidance).
Choosing a contractor
Hire a nationally certified mitigator and ask for a written estimate, clear scope, warranty terms, and post-mitigation testing. North Carolina recommends working with NRPP or NRSB certified pros and following ANSI/AARST standards (NC testing and certification info; NC radon mitigation guidance).
Radon in Cary real estate
Buyers should include radon testing in due diligence and request records for any existing mitigation system. Ask for recent test results, warranties, and system details. If a prior test is old or not documented, request a new test following proper protocols (EPA retesting guidance).
Sellers should disclose known results and any mitigation system information. Addressing a confirmed issue before listing can simplify negotiations and benefit your household now. North Carolina’s statute makes hazardous substances a material fact, so disclose known dangerous levels and provide documentation to buyers (NC disclosure statute; Buyers and Sellers Guide to Radon).
Next steps checklist
- Start with a short-term test and follow closed-house instructions.
- If results are 4.0 pCi/L or higher, do a follow-up test to confirm.
- If confirmed at or above 4.0 pCi/L, consult a certified mitigator and plan post-install testing within 24 hours to 30 days.
- If you have a private well or a high air level, coordinate air and water testing.
- Keep records for your files and future real estate needs.
We’re here to help
Whether you are testing your current home or making a move, you do not have to figure this out alone. If you have questions about timing, contracts, or how radon fits into your due diligence in Cary and across Wake County, reach out to Hendren Realty Group. We can help you plan the right steps and connect you with trusted local resources.
FAQs
Do Cary homes without basements require testing?
- Yes. All home types can have radon, including slab-on-grade, crawlspace, manufactured homes, condos, and basements. Testing is the only way to know your level.
How often should I retest my Cary home?
- Retest after major renovations, changes in occupancy, or if it has been a while since your last test. EPA also advises retesting when you are buying or selling and need current results.
What if my result is 2 to 4 pCi/L?
- Consider reducing levels in this range because there is no known safe level. Confirm your result and discuss options with a certified professional.
How long does mitigation take and how much does it cost?
- Many systems are installed in a day or a few days. Typical projects in North Carolina commonly range around 1,000 to 2,500 dollars depending on your home and system design.
Who should test a home during a sale?
- In real estate transactions, use a certified radon measurement professional who follows recognized protocols and provides a written report. Continuous monitors are commonly used for these tests.
