Radon Mitigation Cost Calculator
| Foundation | Band | Mid |
|---|---|---|
| Slab-on-grade | $800-2,500 | $1,700 |
| Full basement | $900-2,800 | $1,800 |
| Crawlspace | $1,000-3,000 | $2,000 |
Radon mitigation is one of the cheapest major health purchases a homeowner can make: a standard sub-slab depressurization system - one PVC pipe through the slab, one quiet fan, one vent above the roofline - runs $800-2,500 installed, with a national mid-band near $1,700. Foundation type moves the number: basements add about 10 percent for sealing work, crawlspaces 20 percent, and a crawlspace that needs full encapsulation adds $1,500 or more on top.
The reason the number is worth any money: radon is a radioactive gas from uranium decaying in the soil under your house, and it is the second-leading cause of lung cancer after smoking - the EPA estimates it kills about 21,000 Americans a year. Roughly 1 in 15 homes tests above the 4 pCi/L action level, and the owners usually have no idea, because nothing about an elevated house looks or smells different.
The good news is that mitigation works: a properly installed system cuts indoor radon by up to 99 percent, most homes hit below 2 pCi/L, and the system costs pennies a day in fan electricity. The process is honest, too - test first (a $15 kit or a $150 pro visit), mitigate second, test again after to prove the number.
How to use
- Test before you price anything - a short-term charcoal kit or your state's discount program gives a number in days; mitigation without a test number is guesswork.
- Pick the foundation type - slab, basement or crawlspace - and note any sump pits or crawlspaces that need sealing into the suction plan.
- Set the scope: most homes need one suction point; large slabs or tricky footprints need a second, and crawlspace homes often pair with encapsulation.
- Compare two certified-mitigator quotes (your state radon contact lists them), then re-test after installation - the post-test is the only receipt that matters.
Frequently asked questions
How much does radon mitigation cost?
A standard sub-slab system lands mid-band at $1,700 installed ($800-2,500 band) for a slab home, about $1,800 for a basement, $2,000 for a crawlspace - plus $1,500 or more if a crawlspace needs full encapsulation. Complicated footprints needing a second suction point add about $400. Post-mitigation re-testing is $15-150 depending on kit versus professional.
What radon level requires mitigation?
The EPA action level is 4 pCi/L: at or above it, mitigation is recommended, not optional - that concentration carries roughly the lung-cancer risk of a lifetime of moderate exposure to exhaust fumes. Between 2 and 4 pCi/L the EPA suggests considering mitigation anyway, because there is no truly safe level of a radioactive gas in your living room.
How does a mitigation system work?
Beautifully simply: a pipe runs through the slab into the soil gases below, a inline fan runs continuously, and the soil gas is vented above the roofline before it can seep into the house. The house becomes the low-pressure side, so radon never gets pulled in. No filters, no chemicals - just a cleaner pressure gradient and a $10-a-year electricity bill.
Do radon mitigation fans run all the time?
Yes - they are designed for continuous duty, draw about 50-100 watts (roughly $10-15 a year), and run for a decade or more. Most systems include a manometer gauge (a simple U-tube) that shows the fan is pulling; a flat gauge is the one maintenance check that matters, quarterly at a glance.
Can I install a radon mitigation system myself?
Legally in most places, practically unwise: the work involves core-drilling your slab, exterior penetration and flashing, and electrical for the fan - and a botched system can pull conditioned air or sewer gas instead of soil gas. Certified mitigators exist because the design (where to suction, what to seal) matters more than the parts. DIY kits for the TEST are perfectly sensible; DIY for the system is how people pay twice.