Buying a property can feel like a lot. You’re checking the roof, the plumbing, and the wiring. Then someone mentions “radon,” and you’re not sure if it’s a real problem or just another add-on.
- Yes—add radon testing to every property inspection.
- Radon is invisible and odorless, but it’s linked to lung cancer.
- Testing is simple, fast, and affordable.
- If levels are high, proven fixes exist.
- Testing during inspection protects health and your wallet.
In this guide, we’ll explain what radon is, why testing matters, how the tests work, what the numbers mean, and what to do if results are high. I’ll also share a simple checklist, a quick table comparing test types, and a few practical tips so you can act with confidence.
What is Radon?
Radon is a natural gas that comes from the ground. You can’t see it or smell it. It can slip into homes through tiny cracks and gaps.
Info: Radon is formed when uranium in soil and rock breaks down. Outdoors, it spreads out. Indoors, it can build up.
How Radon Gets Inside
Radon travels from soil into basements, crawl spaces, and slabs. It moves through cracks, sump pits, gaps around pipes, and even porous concrete.
Every building can have radon. Old or new. Big or small. With or without a basement.
Why it Matters for Health
Long-term radon exposure can increase the risk of lung cancer. Smokers face an even higher risk when radon is present.
Danger: No amount of radon is “good,” but simple steps can lower it. Testing is the only way to know your level.
When To Test: During Every Inspection
The best moment to test is during your standard inspection window. This keeps the process smooth and gives you time to decide the next steps.
Quick Tip: Ask your inspector to include a radon test add-on in the offer or inspection order. It’s a small step that can prevent big surprises.
Types of radon tests (and which to pick)
There are three common approaches. All can work if used correctly.
| Test Type | Typical Duration | How It Works | Pros | Considerations |
| Short-term charcoal kit | 2–7 days | The passive kit is placed in a central room | Fast and low cost | Snapshot only; can be affected by weather |
| Continuous monitor | 2–7 days | Electronic device records hourly levels | Detailed data; tamper checks | Usually needs a pro; slightly higher cost |
| Long-term alpha track | 90+ days | Passive device tracks over seasons | Most reliable average | Takes time; not ideal if you’re on a tight deadline |
For most real estate timelines, start with a short-term test or a continuous monitor. If results are close to the action level, follow up with a long-term test to confirm.
What The Numbers Mean (And What To Do)
In the U.S., the EPA “action level” is 4.0 pCi/L (picocuries per liter). If your result is at or above 4.0, you should fix the issue. The WHO suggests a lower reference level of about 2.7 pCi/L (100 Bq/m³), which is more conservative.
Fact Box
- 0–2.6 pCi/L: Low. Retest in a couple of years or after major changes.
- 2.7–3.9 pCi/L: Borderline. Consider a long-term test or mitigation.
- 4.0+ pCi/L: High. Plan mitigation with a qualified professional.
How Mitigation Works (Quick Overview)
Most homes are fixed with a system that gently pulls radon from under the slab and vents it outside. A fan runs quietly and continuously.
Many systems are installed in a day by a qualified contractor. After installation, a post-test confirms the improvement.
Suggestion: If you’re buying and the test reads high, request mitigation as part of the agreement or ask for a credit at closing.
Simple Steps To Get Accurate Test Results
A good test is about setup and patience. Keep it boring and steady.
Warnings Box
- Keep windows and exterior doors closed (normal entry/exit is fine).
- Run heating or cooling on normal settings. Don’t “air out” the home.
- Place the device at breathing height in a lived-in room.
- Avoid kitchens, bathrooms, and near exterior doors.
- Retest after big renovations or HVAC changes.
Common Mistakes To Avoid
Don’t skip testing just because the house is new. Don’t rely on a neighbor’s result. And don’t assume “finished basement” means low risk.
If a result is borderline, don’t panic. Confirm with a long-term test or get a pro’s opinion.
Special Cases: Rentals And Multi-Unit Buildings
Rentals benefit from baseline tests plus retests over time. Multi-unit buildings should test ground-contact spaces and randomly sample upper units per local guidance.
Clear records help renters and owners stay on the same page.
Why Radon Belongs In Every Inspection Checklist
Testing during inspection is smart planning. It protects your family, reduces long-term risk, and keeps deals clear.
If levels are high, you can address it before closing or set aside funds. If levels are low, you gain peace of mind and a clean record.
Info: Radon testing is one of the fastest health checks you can add to an inspection. It’s small effort for a big payoff.
The quick path forward
- Ask your inspector to include a radon test.
- Review results and compare to 4.0 pCi/L.
- If high or borderline, plan mitigation or long-term testing.
- Keep proof of results for your records and any future sale.
Conclusion
Radon testing should be part of every property inspection. It’s simple, affordable, and it addresses a real health risk. The data tells you exactly what to do next, and the fixes are proven.
If you’re ready to move forward, consider scheduling with Greenhorn Breckenridge for radon testing. Get the test done, read the results, and make a clear, calm choice.
FAQs
What if I don’t have time for a long test during escrow?
Use a short-term test or a continuous monitor now. If the result is close to the action level, plan a long-term follow-up after closing.
Do I need to test a new home?
Yes. Soil gas doesn’t care about the age of the structure. Many new homes can still have radon.
Is a neighbor’s result good enough for my house?
No. Radon varies lot-to-lot. Your home needs its own test.
How often should I retest?
Retest every two to three years or after major work like finishing a basement or changing HVAC.
Should I test on the upper floors?
Start with the lowest lived-in level. If you plan to use a lower level later, test there too.
