How to Get Your Home Tested for Radon in Virginia

Radon is the second leading cause of lung cancer in the United States, and Virginia homes are far from immune. The western mountain regions, the Piedmont, and parts of Northern Virginia all have areas where indoor radon levels regularly exceed the EPA's 4.0 pCi/L action level. Testing is the only way to know your home's radon level — you can't see, smell, or taste it.

Understanding Virginia's Radon Risk

Virginia's geology creates a patchwork of radon risk across the state. The Blue Ridge Mountains and Shenandoah Valley sit on uranium-bearing rock formations that produce higher radon concentrations. Counties like Fairfax, Loudoun, and Albemarle in Northern Virginia and the Piedmont also show elevated readings, partly due to the underlying metamorphic rock.

The EPA classifies Virginia counties into three zones. Zone 1 (highest risk) covers much of the western part of the state. But even Zone 2 and Zone 3 areas can have individual homes with dangerous levels — radon varies house by house based on foundation type, soil conditions, and construction details.

Testing Options for Virginia Homeowners

There are two main approaches to radon testing, and both are valid starting points.

DIY Test Kits

Charcoal canister tests and alpha track detectors are available at hardware stores and online for $15–$40. Place the kit in the lowest livable level of your home (usually the basement or ground floor), leave it undisturbed for the specified period, then mail it to a lab for analysis. Results come back in 1–2 weeks.

Short-term kits measure over 2–7 days. They're useful as a screening tool, but results can be influenced by weather, HVAC operation, and house ventilation patterns during the test period.

Professional Testing

A certified radon professional places a continuous radon monitor (CRM) in your home for 48 hours under closed-house conditions. The monitor records radon levels hourly, producing a detailed profile rather than a single average. Professional testing typically costs $150–$300 in Virginia.

Professional tests are standard during real estate transactions and provide tamper-evident results that all parties can trust. Browse Virginia radon contractors to find certified testers near you.

How to Prepare Your Home for a Radon Test

Accurate results depend on proper test conditions. For any radon test in Virginia:

• Close all windows and exterior doors for at least 12 hours before the test begins and keep them closed during the test.
• Normal entry and exit through doors is fine — just no extended periods with doors propped open.
• Operate your HVAC system normally. Don't run whole-house fans, window fans, or other ventilation that pulls outside air in.
• Place the test device in the lowest livable area, at least 20 inches off the floor, away from exterior walls, drafts, and humidity sources.
• Don't disturb the test device during the measurement period.

Reading Your Results

Radon levels are measured in picocuries per liter (pCi/L). Here's how to interpret your Virginia test results:

• Below 2.0 pCi/L: Low risk. No action needed, but consider retesting every 2–5 years or after major renovations.
• 2.0–3.9 pCi/L: Moderate. The EPA suggests considering mitigation, especially if you spend significant time in the tested area. A follow-up long-term test can help confirm the average.
• 4.0 pCi/L and above: Action level. The EPA and Virginia Department of Health recommend mitigation. Contact a certified radon mitigator.

A single short-term test above 4.0 pCi/L is enough to justify mitigation. If a short-term test comes back between 2.0 and 4.0, a 90-day long-term test gives a more reliable annual average to base your decision on.

Next Steps After a High Result

If your test comes back at or above 4.0 pCi/L, the standard fix is a sub-slab depressurization system. A certified contractor drills through your foundation, installs piping, and uses a fan to vent radon gas above your roofline. Most installations in Virginia take one day and cost $800–$2,500 depending on home size and foundation type.

Use the mitigation cost calculator to estimate costs for your home. After installation, a post-mitigation test should confirm levels dropped below 4.0 pCi/L.

Finding a Certified Professional in Virginia

Virginia has 63 radon professionals across 47 cities in our directory. When choosing a contractor:

• Verify NRPP or NRSB certification — this ensures they follow national standards for measurement or mitigation.
• Ask whether they carry liability insurance and offer a post-mitigation guarantee.
• Get at least two quotes with written scopes of work before committing.

Northern Virginia homeowners can find contractors serving Fairfax, Arlington, and Loudoun counties. In the Shenandoah Valley and southwestern Virginia, contractors cover broader service areas. Search by your area to see who's nearby using radon contractors near me, or take the radon assessment to get personalized next steps based on your home's situation.