Radon Mitigation Pros in Charleston, SC

Finding a qualified radon mitigation contractor in Charleston shouldn’t require a geology degree and a law degree, but here we are. The local market is a mix of legitimate NRPP-certified specialists and general HVAC guys who added “radon” to their website last Tuesday — and the gap in results between them is not small. This directory cuts through the noise: every contractor listed here holds active certification, which is the only thing standing between a system that actually works and one that looks right but vents radon sideways into your attic.

How to Choose a Radon Mitigation Contractor in Charleston

• Demand the credential, not just the claim. South Carolina has no state radon licensing requirement, which means anyone can legally call themselves a “radon professional.” Ask specifically for an NRPP or NRSB certification number and verify it at nrpp.info before signing anything.
• Separate testing from mitigation. Ideally, hire two different parties — one to test, one to mitigate — to eliminate the obvious conflict of interest. If you use the same contractor for both, confirm they hold separate credentials for measurement and mitigation (the NRPP issues distinct certifications for each).
• Ask about post-mitigation testing. A contractor who installs a system and walks out without scheduling a follow-up test is a red flag. The point is to get below 4 pCi/L; the only way to confirm that happened is another test.
• Get a detailed scope of work in writing. Specifically: number of suction points, fan model and specs, piping route, exterior vs. interior stack, and whether electrical is included or subcontracted.
• Check for a workmanship warranty. Most reputable installers offer a 1- to 5-year warranty on the system. Fan failure is the most common issue — confirm whether the contractor or the fan manufacturer covers replacement.

Pro Tip: Charleston’s housing stock skews heavily toward crawl space foundations, which require a membrane seal in addition to the suction pipe — a step some installers skip or do sloppily. Ask specifically how they handle crawl space encapsulation and whether the cost is included in the quote.

What to Expect

A standard radon mitigation install in Charleston runs $800–$1,500 for most single-family homes; crawl space systems tend to land at the higher end because of the membrane work. Testing-only engagements run $150–$400 depending on whether you go with a short-term (48-hour) or long-term (90-day) test. Most installs are completed in a single day, and post-mitigation test results come back within a week if you use a lab-processed charcoal canister.

Reality Check: If a contractor quotes you under $600 for a full mitigation system, ask hard questions. Low bids almost always mean a single suction point (which may be insufficient for larger footprints), no post-mitigation test, and a builder-grade fan that’ll need replacement in three years. The cheapest option in radon mitigation tends to compound — you pay twice.

Local Market Overview

Charleston sits primarily in EPA Radon Zone 2, meaning predicted average indoor radon levels run between 2 and 4 pCi/L — not Zone 1 panic territory, but not ignore-it territory either. South Carolina imposes no mandatory radon disclosure requirement for real estate transactions, which means sellers have zero legal obligation to tell you about an existing high reading — making buyer-commissioned testing before closing essentially non-optional in this market. The volume of historic homes in the peninsula and older neighborhoods like Wagener Terrace and North Central, many with original foundation systems, creates genuine variability; a neighbor’s clean test doesn’t tell you much about your own crawl space.