Certified Radon Gas Testing in Ellicott City & Howard County, MD
Howard County’s granite bedrock releases radioactive radon through soil fissures. We run certified continuous-monitor testing before you seal a crawl space so the work reduces radon exposure rather than trapping it.
Request Free In-Person Inspection
No obligation. Fixed-price proposal in writing.
Signs your property requires this service
If you are seeing any of these warning signs in your Ellicott City or Howard County home, it is time for a technical inspection.
No prior radon test
A home that has never been tested has an unknown risk that should be measured before sealing work.
Granite-bedrock lot
Howard County’s Piedmont granite is a known radon source, raising the priority of testing.
Planned encapsulation
Sealing a crawl space without testing radon first can concentrate the gas indoors.
Real estate transaction
Buyers and sellers often need a certified radon result as part of due diligence.
Our step-by-step engineering standard
- Phase 1
Placement & protocol setup
We place a continuous radon monitor (CRM) in the lowest livable area under controlled, closed-house conditions.
- Phase 2
48-hour continuous measurement
The CRM records an hour-by-hour radon profile over a 48-hour protocol for an accurate, tamper-resistant reading.
- Phase 3
Analysis vs. action level
We analyze the profile against the EPA 4.0 pCi/L action level and interpret the hourly variation.
- Phase 4
Mitigation readiness
Where results warrant it, we prepare the encapsulation for sub-membrane passive or active depressurization (soil suction).
Technical standards & material specifications
- EPA radon measurement protocol
- ANSI/AARST standards
- EPA 4.0 pCi/L action level
- Primary Symptom
- No prior radon test, granite-bedrock lot, planned encapsulation
- Technical Solution
- 48-hr continuous monitor + sub-membrane depressurization readiness
- Governing Code / Standard
- EPA protocol · ANSI/AARST · 4.0 pCi/L
- Expected Lifespan
- Re-test every 2 years
Why Howard County homes need this
Howard County’s native granitic Piedmont bedrock releases radioactive radon gas through soil fissures, and the county has areas of documented elevated radon potential.
Sealing a crawl space without first measuring radon risks concentrating the gas indoors. Testing confirms whether your soil gas is safe and ensures any sealing work reduces exposure rather than trapping it beneath the home.
The Stack Effect
Up to 50% of the air on your main floors originates below grade. That is why a crawl space mold problem shows up as headaches, congestion, and musty HVAC return air two floors up — remediating the source is the only durable fix.
Investment & ROI for this service
Typical Howard County range
$150 – $300
What affects the price
Continuous-monitor placement, number of test locations, and turnaround requested.
Long-term value
Confirms whether your soil gas is safe and ensures sealing work reduces radon exposure rather than trapping it.
Every project is quoted with a fixed, written proposal after a free on-site inspection — no obligation.
Frequently asked questions
Is radon really a concern in Howard County?
Yes. The county sits on granitic Piedmont bedrock that releases radon through soil fissures, and it includes areas of elevated radon potential. Testing is the only way to know your home’s level.
Why test before encapsulating?
Sealing a crawl space changes how soil gas moves. Without a baseline radon test, sealing can inadvertently concentrate radon indoors. Testing first lets us build in sub-membrane depressurization where needed.
What is the action level?
The EPA action level is 4.0 pCi/L. At or above that, mitigation is recommended. Our continuous-monitor protocol measures against that threshold with an hour-by-hour profile.
How often should I re-test?
The EPA recommends re-testing every two years, and after any major foundation or crawl-space work that changes how soil gas enters the home.