Radon Mitigation Pros in San Antonio, TX

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Finding a qualified radon mitigation contractor in San Antonio shouldn’t be a weekend research project — but between unlicensed handymen advertising on Nextdoor and national chains that quote over the phone without ever seeing your foundation, it usually turns into one. This directory cuts through that noise: every pro listed here holds active NRPP or NRSB certification, which means they’ve passed the exams, carry the insurance, and know the difference between a measurement report and a mitigation warranty.

How to Choose a Radon Mitigation Contractor in San Antonio

• Verify certification before anything else. Texas has no state radon licensing law — which means literally anyone can call themselves a radon contractor. The only credential that means something is NRPP or NRSB certification. Look up their cert number at aarst-nrpp.com before you schedule a call.
• Don’t use the same company for testing and mitigation. If a contractor sells you the test and the fix, they have a financial incentive to find a problem. Use a certified measurement professional for your initial test, then hire a separate mitigation specialist if levels come back above 4 pCi/L.
• Ask for a post-mitigation test, in writing. Any reputable contractor will include a follow-up measurement 24–48 hours after system installation. If they don’t offer it, or charge extra for it, walk away.
• Get the system design explained to you. San Antonio sits in EPA Zone 2 (moderate potential), but homes in the far northwest corridors — near Helotes and Leon Valley — have seen test results well above 10 pCi/L. A contractor who gives you a one-size-fits-all quote without inspecting your slab type, crawlspace configuration, and HVAC layout is guessing.
• Check the warranty terms carefully. Systems should carry at minimum a one-year labor warranty and a lifetime warranty on the fan. Some contractors offer radon-level guarantees (sub-4 pCi/L or they come back free). That’s the standard worth holding out for.

Pro Tip: Ask if the contractor uses a manometer on every install. This simple pressure gauge confirms the system is actually drawing suction from under the slab — without it, there’s no way to know the fan is working correctly until your next test.

What to Expect

A standalone radon test in San Antonio runs $150–$400 depending on whether you use a short-term (48-hour) or long-term (90-day) monitor; if you’re in the middle of a real estate transaction, assume short-term. Full mitigation installs — typically an active soil depressurization system with an exterior pipe run and inline fan — land between $800 and $1,500 for most single-family homes, with larger or multi-entry-point foundations pushing toward $2,000. Most installs take four to six hours; you’re back to normal life the same day.

Reality Check: The biggest pricing mistake homeowners make is accepting a phone quote. Square footage doesn’t determine system complexity — your foundation type does. A pier-and-beam house in Alamo Heights requires a completely different approach than a slab-on-grade home in Stone Oak, and a contractor who doesn’t ask about your foundation before quoting is either guessing or padding the price to cover surprises.

Local Market Overview

Texas doesn’t mandate radon disclosure at the point of sale — meaning sellers have no legal obligation to test, and buyers often don’t know to ask — which makes San Antonio one of the more underserved markets in the region despite sitting adjacent to higher-risk Hill Country geology. If you’re buying in the 78256, 78255, or 78249 ZIP codes, a pre-closing radon test isn’t optional; it’s the one $200 line item that can save you a $1,200 retrofit six months after you move in.