A short-term radon test is the fastest way to find out whether radon gas is building up in your home. Most tests run between 48 and 96 hours, and the results tell you whether your levels are above the EPA action level of 4.0 pCi/L. In Atlanta, this type of test is the standard choice for real estate transactions and for homeowners who want an answer quickly.
What a short-term radon test actually is
Radon is a colorless, odorless gas that seeps up through soil and into buildings through cracks in slabs, foundation walls, and any other gap between the ground and the living space. You cannot smell it or see it. The only way to know your level is to measure it.
A short-term test uses either a charcoal canister or a Continuous Radon Monitor, often called a CRM. The charcoal canister is a passive device that absorbs radon particles from the air over the test window and is then sent to a lab for analysis. A CRM is an active electronic device that logs radon concentrations hour by hour and produces a report immediately at the end of the test. Both methods are recognized under ANSI/AARST radon standards.
For
residential radon testing in Atlanta, we use continuous radon monitors on most jobs because they deliver results the same day the test ends, with an hourly data log that shows whether house conditions stayed stable throughout.
What is the difference between a short-term and long-term radon test?
A short-term test runs for 48 to 96 hours under closed-house conditions and gives you a fast snapshot. A long-term test runs for 90 days or more using an alpha track detector and gives you a seasonal average that reflects how the house actually breathes over time.
Short-term tests are the right choice when you are under a real estate deadline or want a quick baseline reading. Long-term tests are better suited for confirming a borderline result or monitoring a home over time after mitigation. If a short-term test comes back between 2.7 and 4.0 pCi/L, which is above the WHO reference level but below the EPA action level, a follow-up long-term test is often the next sensible step. Our
long-term radon testing service covers exactly that situation.
| Test type |
Duration |
Device used |
Best for |
| Short-term |
48 to 96 hours |
Charcoal canister or CRM |
Real estate, quick baseline |
| Long-term |
90 days or more |
Alpha track detector |
Seasonal average, post-mitigation confirmation |
Is radon a real problem in Atlanta, even in a warm climate?
Yes. Many homeowners assume Georgia’s warm weather means radon is not a concern. That assumption is wrong.
North Georgia sits on granite and gneiss bedrock. Both rock types naturally contain uranium, which decays into radium, which decays into radon gas. That geology runs through Cherokee, Cobb, Fulton, Forsyth, DeKalb, and Pickens counties, all areas we regularly test. The EPA designates parts of North Georgia as Zone 1 and Zone 2, meaning elevated radon potential. Warm climate has little bearing on what comes up through the ground.
Basements and slab-on-grade construction both trap radon. Atlanta has plenty of both. A finished basement used as a bedroom, a playroom, or a home office can accumulate radon at levels well above the EPA action level of 4.0 pCi/L, and occupants would never know without testing.
Which radon test is required when buying or selling a home in Atlanta?
Georgia does not mandate radon testing by law, but the Georgia Seller’s Property Disclosure Act under O.C.G.A. § 44-1-16 requires sellers to disclose known environmental hazards. Because of this, radon testing has become a standard part of real estate due diligence across the Atlanta metro.
Buyers typically request a short-term test during the inspection period because the timeline fits the contract window. Results are available before closing, which gives both parties time to negotiate remediation if levels are high. Sellers who test before listing remove the uncertainty entirely.
For a transaction where results need to hold up to scrutiny, you want a
certified radon testing professional who follows ANSI/AARST protocols and provides a written report, not just a number on a slip of paper.
How long does a professional short-term radon test take?
The test device sits in the lowest livable area of the home for a minimum of 48 hours, and most professionals run it for 96 hours to improve accuracy. Setup takes about 15 to 20 minutes. If we are using a CRM, we retrieve the device at the end of the test window and generate the report on-site. Lab-based charcoal canisters take a few additional days for processing after pickup.
From first contact to written results, most short-term tests are complete within four to five business days. For real estate transactions with tight deadlines, we schedule quickly and can often start within 24 to 48 hours of booking.
What happens during the test: closed-house conditions explained
Closed-house conditions are required for the entire test period, starting at least 12 hours before placement. That means:
- Windows and exterior doors stay closed except for normal entry and exit
- Whole-house fans and window-mounted air conditioners are turned off
- Central HVAC can run normally on its regular thermostat cycle
- Fireplaces should not be used during the test
These conditions prevent outdoor air from artificially diluting the radon reading, which would give you a falsely low result. Violating closed-house conditions invalidates the test under ANSI/AARST standards. We explain all of this clearly before placement so there are no surprises.
What radon level requires action in Georgia?
The EPA action level is 4.0 pCi/L. At or above that level, the EPA recommends mitigation. The World Health Organization sets a stricter reference level of 2.7 pCi/L.
There is no radon level that is completely risk-free. Even 2.0 pCi/L carries some exposure. But practically speaking, most mitigation contractors in Georgia treat 4.0 pCi/L as the threshold for recommending a system, and 2.7 to 4.0 pCi/L as a gray zone where a follow-up long-term test is worth considering.
For a clear picture of where your home stands against these benchmarks, a
radon level assessment gives you the numbers and the context to make a decision.
What happens after the test comes back high?
If your short-term test result is at or above 4.0 pCi/L, the next step is mitigation. The standard method for slab-on-grade and basement homes in Atlanta is Active Sub-Slab Depressurization, where a suction point is drilled through the concrete slab, PVC pipe is routed to the exterior, and an inline radon fan draws gas out from under the foundation before it enters the home.
For crawl space homes, Sub-Membrane Depressurization is the method: a vapor barrier is sealed across the crawl space floor and a fan draws radon out from beneath it.
After any mitigation system is installed, a post-mitigation verification test is required within 30 days to confirm the system is working. We handle both the testing and the mitigation work, so you do not have to coordinate between two separate companies.
Mitigation costs vary depending on foundation type, system complexity, and site conditions. We do not publish a flat price because a crawl space job and a finished basement with sump pit access are different scopes of work. We provide a written estimate after the test.
Why choose a certified radon testing professional
Anyone can buy a charcoal canister at a hardware store. What you get from a professional is different: proper device placement following ANSI/AARST protocols, a written report with chain-of-custody documentation, and a technician who can explain what the numbers mean and what your options are.
For real estate transactions, certification matters. Lenders and real estate agents regularly ask whether the test was conducted by an NRPP or NRSB certified professional. A self-administered test from a box store often does not meet that standard and cannot be used in a negotiation.
Our technicians are certified and follow established radon measurement standards on every job across Cobb, Fulton, DeKalb, Forsyth, Hall, Newton, Clayton, Gordon, Pickens, and Douglas counties.
Frequently asked questions
Should I get a radon test before closing on a home in Atlanta?
Yes. Request it during the inspection period so results are back before the deadline. If levels come back at or above 4.0 pCi/L, you have time to negotiate repairs or a price adjustment before you are locked in.
What is the average radon level in Atlanta GA homes?
Georgia does not publish a single statewide average, and county-level data varies. North Georgia counties built on granite bedrock tend to test higher than coastal areas. The only reliable number is the one from your specific home. Geology and neighborhood averages do not tell you what is under your slab.
Can I use a store-bought test kit instead?
You can, but store-bought charcoal canisters only work if placement, closed-house conditions, and lab submission are handled correctly. For a real estate transaction, most buyers and sellers need a certified professional’s report. For a personal baseline reading in a home you already own, a quality DIY kit is a reasonable starting point, though it will not give you the hourly data log a CRM produces.
How much does radon mitigation cost in Atlanta GA?
System cost depends on foundation type and site conditions. Simple slab systems with a single suction point cost less than crawl space jobs requiring a full vapor barrier. We provide a written estimate after testing is complete and we have seen the home.
Does radon come back after mitigation?
A properly installed and maintained Active Sub-Slab Depressurization system keeps drawing soil gas out continuously as long as the fan runs. The fan is the only mechanical component, and they are designed to run constantly for years. We recommend testing again every two years and immediately any time you make structural changes to the foundation or lowest level.
