Sub-Slab Depressurization
A suction pit is created beneath the slab, a PVC pipe routes from that pit through the structure, and a radon fan exhausts the gas above the roofline. This is the standard and most effective residential method.
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Radon Mitigation Systems
Sub-slab depressurization installed correctly the first time, by a contractor who's been in the trade for over 20 years.
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How Radon Mitigation Protects Your Home
Radon mitigation is the process of installing a ventilation system that draws radon gas from beneath your home's foundation and exhausts it safely outside before it can accumulate to dangerous levels indoors. Greater Charlotte Contracting installs radon mitigation systems throughout the Greater Charlotte metro, combining genuine construction knowledge with an understanding of how these homes are actually built. Radon is the second leading cause of lung cancer in the United States, and the EPA recommends action any time a test reads 4 pCi/L or higher. If you've tested your home and gotten that number, don't sit on it. Call (704) 957-5323 and we'll scope the work honestly.
Most residential radon mitigation uses sub-slab depressurization: a pipe penetrates the slab or block foundation, a dedicated fan pulls radon-laden soil gas upward, and the exhaust discharges above the roofline or through an exterior wall away from windows and doors. What separates a system that actually works from one that just looks like it works is correct fan sizing, proper pipe routing, and an airtight penetration seal at the slab. Shortcuts at any of those points leave elevated radon in the living space. Cost varies based on foundation type, slab accessibility, pipe routing distance, fan specifications, and whether finishing work is needed around the penetration. Every job is different -- contact Greater Charlotte Contracting for an accurate estimate.
The Science
What Radon Mitigation Actually Does
A properly installed system doesn't mask the problem -- it eliminates the pathway radon uses to enter the home.
Fan Sizing and Placement
The wrong fan does real harm -- too weak and it can't overcome soil resistance, too strong and it can depressurize the living space and pull conditioned air out. Proper sizing requires measuring sub-slab communication before specifying the unit.
Airtight Penetration Sealing
Where the pipe passes through the slab, the annular gap gets sealed with hydraulic cement and expanding foam. An unsealed penetration defeats the pressure differential the system depends on.
Post-Installation Testing
A mitigation system isn't confirmed effective until you test. We recommend a short-term or long-term radon test after installation. The number on that test is the only honest measure of whether the system is working.
How It Works
The Installation Process, Step by Step
Radon mitigation installation is typically a one-day job when the foundation and routing conditions are straightforward. Here's what that day looks like.
- 01
Site Assessment
We evaluate your foundation type, slab thickness, utility locations, and the most direct pipe routing to an appropriate exhaust point. This determines fan specifications and material requirements before a single hole is drilled.
- 02
System Installation
A suction pit is cored through the slab, the pipe is routed and supported, the fan is mounted and wired, and all penetrations are sealed. The exhaust terminates above the roofline or at an approved exterior location away from windows.
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Verification and Handoff
We confirm the system is operating correctly, explain the pressure indicator gauge so you know at a glance if the fan has stopped running, and walk you through scheduling a post-installation radon test.
Radon in Greater Charlotte Area Homes
North Carolina's geology puts a meaningful portion of the state in EPA Zone 2, which means predicted average indoor radon levels between 2 and 4 pCi/L -- close enough to the action threshold that testing before renovation is genuinely important, not just cautious. Older homes and homes with unfinished basement remodel spaces or crawl spaces tend to accumulate higher levels because more foundation surface is in contact with the soil. Homes in Huntersville, Mint Hill, and the surrounding communities with slab-on-grade foundations aren't exempt either -- radon can enter through any concrete-to-soil interface.
If you're planning a basement remodel or any work that involves sealing or finishing a lower level, radon testing and mitigation should happen before that work begins. Enclosing a space that already has elevated radon and then finishing it creates a problem that's significantly harder and more expensive to address afterward. The owner of Greater Charlotte Contracting has been working in residential construction for over 20 years. He's seen what happens when mitigation gets treated as an afterthought. It doesn't.
At a Glance
Key Facts About Radon Mitigation
Structured for clarity -- these are the facts that matter most when you're deciding whether to act.
- 01
The EPA action level is 4 pCi/L
At or above this level, the EPA recommends mitigation. The average indoor radon level in US homes is 1.3 pCi/L. A reading of 4 or higher is a clear signal to install a mitigation system.
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Homeowners insurance typically does not cover radon mitigation
Radon is considered a pre-existing environmental condition, not sudden damage. Most standard policies exclude it. Some home warranty plans include testing but not mitigation installation.
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Sub-slab depressurization reduces radon by 80 to 99 percent in most homes
This is the EPA-preferred method for slab-on-grade and basement foundations. Results depend on proper fan sizing and seal integrity at the slab penetration.
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Testing after installation is non-negotiable
A system that looks right may not perform correctly if sub-slab communication is poor or the fan is undersized. The post-installation test confirms actual reduction and gives you a documented baseline.
Why This Work Gets Done Right or Gets Redone
- 01
Honest Assessment Before Any Work Starts
We don't spec a system until we understand the foundation, the soil communication, and the routing constraints. That assessment is what prevents an undersized fan or a pipe that dead-ends in poor sub-slab material.
- 02
Materials and Methods That Actually Work
Schedule 40 PVC, code-compliant penetration sealing, properly rated radon fans from manufacturers with real warranties. We're not buying the cheapest components and hoping the test comes back clean.
- 03
Transparent Scope, No Invented Line Items
The estimate you receive describes exactly what's being installed and why. If your foundation type or routing conditions require something extra, you'll know before work starts -- not when the invoice arrives.
Related Work We Handle in the Same Visit
01
Basement Remodel
Finishing or renovating a basement? Radon testing and mitigation should precede any enclosure work. We handle both so the sequence is correct.
02
Restoration
Water intrusion and radon entry often share the same pathways. Foundation cracks that let moisture in also let radon in. We address both when the scope calls for it.
03
Handyman Services
Smaller jobs around the lower level -- sealing cracks, patching penetrations, repairing interior access points -- can run alongside the mitigation work rather than requiring a separate call.
What You Can Verify About This Work
Clint at Greater Charlotte Contracting carries 20-plus years of construction experience and a 5-star rating across 17 Google reviews. Here's what that actually means for radon mitigation work.
Owner-operated means the person who scoped your job is the person on-site. There's no crew hand-off, no subcontractor who didn't hear the conversation about your foundation's quirks. The same hands that do the site assessment install the system.
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Licensed contractor in NC
Verifiable through the NC Licensing Board -- not a claim, a credential.
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5.0 stars across 17 Google reviews
Every review names the owner by name. Read them before you call.
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Owner on-site, not managing from an office
20+ years of hands-on construction experience means he's seen how these systems fail. He installs them correctly the first time.
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Available Monday through Friday, 8AM to 6PM
No emergency-service promises. Straightforward availability and honest scheduling.
FAQs
Radon Mitigation -- Specific Questions Answered
What is radon gas and why does it matter in residential homes?
Radon is a naturally occurring radioactive gas produced by the decay of uranium in soil, rock, and groundwater. It's invisible and odorless, which is why testing is the only way to know if it's present. The EPA lists radon as the second leading cause of lung cancer in the US after smoking, responsible for roughly 21,000 deaths annually. In homes, it accumulates through foundation penetrations and slab joints, especially in lower levels where ventilation is limited.
What does a radon mitigation system actually do to reduce levels?
A sub-slab depressurization system creates a zone of negative pressure beneath the foundation by drawing soil gas outward through a dedicated pipe and fan assembly. Radon follows the path of least resistance -- out through the pipe instead of up through the slab into the living space. Most properly installed systems reduce indoor radon concentrations by 80 to 99 percent, confirmed by post-installation testing. The fan runs continuously; it's sized for your specific foundation conditions.
Will homeowners insurance cover radon mitigation costs?
Standard homeowners insurance policies do not cover radon mitigation. Radon is classified as a pre-existing environmental condition rather than sudden or accidental damage, which puts it outside most policy definitions of covered loss. Some home warranty plans include radon testing but not system installation. If you're purchasing a home and radon is flagged on inspection, the mitigation cost is frequently a negotiable item in the sale contract.
How much does radon mitigation cost, and what drives the price?
Cost depends on foundation type, slab thickness, sub-slab communication quality, pipe routing distance, fan specifications, and whether any finishing or patching work is needed around the penetration. A straightforward slab-on-grade installation with a direct exterior routing route costs less than a basement with complex utility obstructions or poor sub-slab aggregate that requires multiple suction points. Every job is different -- contact Greater Charlotte Contracting for an accurate estimate.
Can radon enter a home that doesn't have a basement?
Yes. Slab-on-grade homes have the entire foundation footprint in direct contact with the soil, which makes them as susceptible as basement homes. Radon enters through the slab itself -- via micro-cracks, cold joints, and utility sleeve penetrations -- not only through foundation walls. Crawl space homes have their own exposure pathway through the subfloor. Foundation type determines the mitigation method, not whether mitigation is necessary.
Does radon mitigation need to be done before finishing a basement?
Yes -- and this is the order that matters. Finishing a basement creates enclosed habitable space at the level where radon concentrates. If you enclose and finish first and test afterward, the remediation is significantly more complex because you've buried the slab and limited pipe routing options. Test and mitigate before the basement remodel begins. The sequencing isn't optional if you want both a clean test result and a finished space that wasn't more expensive to remediate.
How do I know if my radon mitigation system is still working?
Installed systems include a visual pressure indicator, typically a U-tube manometer mounted on the suction pipe. If the fluid levels in both arms are equal, the fan has stopped operating and the system isn't working. Beyond that visual check, re-testing every two years is the recommended practice. Fan motors have finite lifespans and can fail quietly. A periodic test is the only way to confirm the system is still performing at the levels documented after installation.
Areas We Serve
Greater Charlotte Contracting installs radon mitigation systems throughout the Greater Charlotte metro and surrounding communities. We're available Monday through Friday, 8AM to 6PM.
Get an Accurate Estimate on Radon Mitigation
If your test came back at 4 pCi/L or higher, the path forward is straightforward. Call Greater Charlotte Contracting and we'll scope the installation honestly.