A radon mitigation system installation typically takes one day. A certified technician drills a suction point through your slab or installs a sub-membrane barrier in a crawl space, routes PVC pipe to the exterior, and connects an inline radon fan that pulls soil gas out before it enters your living area. When the work is done, a post-mitigation test confirms the result.
What radon mitigation system installation actually involves
The core of the work is Active Sub-Slab Depressurization, usually called ASD. A suction pit is drilled through the concrete slab, PVC vent pipe runs from that point up through the home or along the exterior wall, and a radon fan pulls air continuously from beneath the slab and exhausts it above the roofline. That negative pressure zone keeps soil gas from migrating up through cracks, joints, or penetrations into your home.
For homes with crawl spaces, the method is Sub-Membrane Depressurization. A vapor barrier seals the crawl space floor, and the fan system draws radon-laden air from beneath that membrane before it can move into the conditioned space above.
The only mechanical component that moves is the radon fan. Everything else is PVC pipe, fittings, and a manometer, which is a small U-tube pressure gauge mounted on the pipe so you can see at a glance that the system is working.
Before installation begins, a
radon level assessment establishes your baseline reading. That number determines how much suction the system needs and helps size the fan correctly.
What radon level requires mitigation in Georgia?
The EPA action level is 4.0 pCi/L (picocuries per liter). At or above that concentration, the EPA recommends mitigation. The WHO reference level is 2.7 pCi/L, and many professionals treat that as the practical threshold worth acting on.
Georgia’s geology matters here. North Atlanta counties sit on granite and gneiss bedrock, and that rock releases radon naturally as uranium decays. Fulton, Cobb, DeKalb, Forsyth, Cherokee, and surrounding counties carry elevated baseline risk. Several of these counties fall in EPA Radon Zone 1, the highest-risk classification. If your home hasn’t been tested, the geology alone is a reason to start with
residential radon testing.
Does my foundation type affect which system I need?
Yes, directly.
| Foundation type |
Primary method |
Notes |
| Basement with poured slab |
Active Sub-Slab Depressurization (ASD) |
Most common install in Atlanta |
| Slab-on-grade |
Active Sub-Slab Depressurization (ASD) |
Suction point location matters more |
| Crawl space |
Sub-Membrane Depressurization (SMD) |
Vapor barrier required |
| Mixed (part slab, part crawl) |
Combined ASD and SMD |
Two-zone system |
| Sump pit present |
Sump pit depressurization |
Existing penetration used as suction point |
If you have a sump pit, that penetration is often the most efficient entry point for the suction pipe, and it can simplify the install. Your technician will assess sub-slab communication first, meaning they’ll confirm that suction at one point actually draws air across the slab area rather than pulling from a single isolated pocket.
How the installation process works, start to finish
Day before or morning of: A technician reviews your floor plan, walks the basement or crawl space, and selects the suction point location. Good placement matters. A suction point in a corner with limited communication to the rest of the slab will underperform.
Drilling the suction pit: A core drill cuts through the concrete, typically a four-inch diameter hole. The technician removes debris and checks for sub-slab aggregate or fill material that will allow air to move freely.
Pipe routing: Schedule 40 PVC runs from the suction pit vertically or along the wall to the exterior. Pipe is sealed at every penetration. The exhaust point is positioned above the roofline and away from windows, doors, and HVAC intakes so the exhausted soil gas disperses rather than re-entering the building.
Fan installation: The inline radon fan mounts on the pipe, usually in the garage, attic, or on the exterior wall. The fan selection depends on the sub-slab resistance and the volume of air that needs to move.
Manometer installation: A U-tube manometer is mounted in a visible spot on the pipe, typically in the basement or garage. It shows pressure differential so you can confirm the system is running correctly without any tools.
Site cleanup and walkthrough: The technician walks you through how to read the manometer, what the normal operating range looks like, and when to call if something changes.
Our technicians carry NRPP or NRSB certification and work to ANSI/AARST installation standards. Those standards specify pipe sizing, fan placement, exhaust location, and post-installation testing requirements. You can verify a technician’s certification status through the AARST-NRPP database before anyone arrives at your door.
How long does radon mitigation installation take?
Most single-family home installations take four to eight hours. A straightforward basement with one suction point and a clean pipe route to the exterior is on the shorter end. A home that needs two suction points, a long pipe run, or a combined slab-and-crawl-space system takes longer.
You can be home during the work. The drilling is loud for a short period, but there’s no need to vacate.
How much does radon mitigation cost in Atlanta?
Costs vary based on foundation type, number of suction points needed, pipe routing distance, and fan selection. A single-suction-point ASD system in a standard Atlanta basement will cost less than a multi-point system in a complex split-level. Crawl space jobs require a vapor barrier if one isn’t already installed, which adds to the total.
Get a written estimate that itemizes the fan model, number of suction points, pipe routing plan, and whether post-mitigation testing is included. A quote that skips those details is hard to compare against anything.
If you’re selling your home, the Georgia Seller’s Property Disclosure Act under O.C.G.A. § 44-1-16 requires disclosure of known radon issues. A documented professional installation with test results is the cleanest way to handle that obligation.
Is DIY radon mitigation as effective as professional installation?
DIY kits exist, but the results are inconsistent. The two main problems are suction point placement and fan sizing. A technician tests sub-slab communication before drilling, meaning they verify that the suction point will actually pull air from beneath the full slab area. A homeowner guessing at placement may install a system that works in one room and does little in another.
Fan sizing is the second issue. Undersized fans won’t create enough negative pressure. Oversized fans can depressurize the slab aggressively and pull conditioned air out of the building envelope, raising energy costs.
For a certified result that satisfies a buyer’s inspection or an insurance requirement, professional installation with a documented post-mitigation test is the only option that holds up.
How do I know if my existing radon mitigation system is still working?
Check the manometer first. It’s the small U-tube gauge mounted on the pipe. If the fluid levels in both sides of the tube are equal, the fan has stopped moving air. You should see a visible difference between the two sides during normal operation.
Beyond the visual check, radon fan motors do fail over time. If the manometer looks wrong, listen for the fan. A running fan you can hear is reassuring, but some fans fail silently, spinning without creating sufficient pressure. A
certified radon testing test after any concern is the definitive answer.
Signs that a system may not be performing:
- Manometer shows no pressure differential
- Fan is audibly louder or quieter than usual
- It has been more than two years since the last radon test
- The home has been renovated and the slab was disturbed
How do I read my radon mitigation system’s manometer?
A manometer is a clear plastic U-tube partially filled with colored fluid. During normal operation the fluid in the side connected to the suction pipe sits lower than the fluid in the open side. That difference in height shows negative pressure, meaning the fan is pulling air from beneath the slab.
If the fluid levels are equal, there is no pressure differential and the system is not working. Your technician will mark the normal operating range on the manometer during installation. If the fluid drops below that mark or rises above it, call for a check.
How often should I retest after a mitigation system is installed?
A post-mitigation verification test is required within 30 days of installation. This test confirms the system achieved the goal, which is radon below 4.0 pCi/L and ideally below 2.7 pCi/L.
After that, retest every two years under normal conditions. Retest sooner if:
- The fan was replaced
- You finished a basement or changed the floor plan significantly
- You noticed a change in the manometer reading
- You’re preparing to sell the home
Short-term tests using a charcoal canister work for post-mitigation verification. Long-term tests using an alpha track detector give a more accurate picture of annual average exposure. A continuous radon monitor provides real-time readings if you want ongoing visibility.
All of this connects back to the broader work we do under
environmental health service services. Mitigation is the fix, but testing is how you know the fix worked and stays working.
Frequently asked questions
Will the radon fan run constantly? Yes. Radon fans run continuously. They’re designed for that, draw low wattage, and most homeowners never notice them after installation.
Does the pipe have to go through the roof? The exhaust must terminate above the roofline or in a location that prevents re-entry. Exterior wall routing that terminates above the eave line is acceptable in many configurations. Your technician will review local code requirements.
Can a system be installed in a finished basement? Yes, though it may require more planning around the pipe route. Pipe can often run inside a closet, a utility chase, or along an exterior wall with a paintable cover.
What if my radon test comes back below 4.0 pCi/L but I’m still concerned? The WHO reference level of 2.7 pCi/L is a reasonable target. If your reading is between 2.7 and 4.0 pCi/L, mitigation is optional but worth discussing, especially in a home where young children spend significant time indoors.
