Price guide · Ducts & Air Quality
Radon Mitigation System Cost
Radon mitigation system, installed
Quick answer: Installing a radon mitigation system costs $1,200 to $2,000 on average, with a national average of $1,600, according to HomeGuide. Angi reports a lower average of $1,043 and a typical range of $805 to $1,326. Active sub-slab depressurization, the most common method, runs $1,000 to $3,000. Professional radon testing costs $125 to $700.
HomeGuide puts a typical system at $1,200 to $2,000, with a national average of $1,600. Angi's average, based on 1,184 projects, is $1,043, with most installs between $805 and $1,326.
Cost by method
| Method | HomeGuide | Angi |
|---|---|---|
| Active sub-slab depressurization | $1,200 – $2,000 ($2,500+ larger homes) | $1,000 – $3,000 |
| Passive depressurization | – | $500 – $2,500 |
| Wall-based system | – | $500 – $3,000 |
| Ventilation system | – | $1,300 – $2,500 |
| Basement sealing | $6,000 – $18,000 | $400 – $4,600 |
| Crawl space encapsulation | $3,000 – $15,000 | $1,500 – $15,000 |
| Radon in water (aeration) | – | $1,200 – $5,000 |
HomeGuide calls active soil depressurization the most common system type: a fan vents radon from beneath the foundation. Angi says it uses PVC pipe to draw gas from beneath the floor or crawl space. Angi says sealing the basement is only about half as effective as other methods.
Testing
| Test | HomeGuide | Angi |
|---|---|---|
| Professional test | $125 – $400 | $150 – $700 |
| DIY test kit | $10 – $30 | $15 – $60 |
| Digital radon detector | $150 – $300 | – |
HomeGuide notes some states offer free short-term test kits.
Other costs
| Item | Cost | Source |
|---|---|---|
| Permit | $25 – $150 | HomeGuide, Angi |
| Electrician, if needed | $50 – $100 per hour | Angi |
| Larger home | $500 – $1,500 more | Angi |
| Extended warranty | $200 – $500 | Angi |
Running costs
HomeGuide puts fan electricity at about $70 to $80 per year, similar to a 60-watt bulb. Angi lists $100 to $300 per year. Both say the fan may need replacement after roughly 5 to 10 years; HomeGuide notes many manufacturers offer a 5-year fan warranty.
What radon is
Radon is a colorless, odorless radioactive gas that comes from the natural breakdown of uranium in soil and rock. It can enter a home through cracks in the foundation, gaps around pipes and other openings. Long-term exposure is a known cause of lung cancer.
Testing comes first
The only way to know the radon level in a home is to test it. Short-term test kits are widely available, and long-term tests give a better picture of average levels. Professional testing is also an option, especially during a home sale.
How mitigation works
The most common method is active soil depressurization. A contractor installs a pipe through the foundation slab or crawl space and a fan that pulls radon from under the house and vents it above the roof. Sealing cracks and openings helps the system work better.
What affects the price
- Foundation type: slab, basement or crawl space.
- How easily the pipe can be routed through the house or along the outside.
- Number of suction points needed.
- Fan type and electrical work.
- Follow-up testing after installation.
After installation
The system should include a gauge that shows whether the fan is working. Retest after the system is installed, and again from time to time, to confirm levels have dropped.
Questions to ask
- Are you certified in radon mitigation?
- Will you do a post-installation test?
- Where will the pipe run, and what will it look like from outside?
In Texas
Radon levels vary by location, and many Texas homes are built on slab foundations. Since levels can differ even between neighboring houses, testing your own home is the only reliable way to decide whether mitigation is needed.
Understanding your test results
Radon is measured in picocuries per liter of air (pCi/L). The EPA recommends fixing a home if the radon level is 4 pCi/L or higher, and suggests considering mitigation for levels between 2 and 4 pCi/L. Because there is no known safe level, lower is better.
A short-term test, which lasts a few days, gives a quick result. A long-term test, which lasts more than 90 days, shows the average level over seasons. If a short-term test shows a high level, the EPA suggests a follow-up test before deciding, unless the first result is very high.
How sub-slab depressurization works
The most common mitigation method is sub-slab depressurization. A contractor drills a hole through the basement or slab floor, removes some soil or gravel to create a suction pit, and installs a PVC pipe from the pit to a fan. The fan pulls radon-laden air from under the house and vents it above the roofline, where it disperses. The fan runs continuously.
Homes with crawl spaces may need a sealed vapor barrier over the soil with a suction point under it. Homes with sump pits can often use the sump as a suction point by sealing its lid.
Sealing cracks
Contractors usually seal visible cracks and openings in the foundation as part of the system. Sealing alone is rarely enough to lower radon significantly, but it helps the fan system work better.
The manometer
A U-shaped gauge called a manometer is installed on the pipe. It shows whether the fan is creating suction. If the liquid levels become even, the fan may have stopped. Check it regularly.
More on after installation
The EPA recommends testing again after the system is installed to confirm it lowered the radon level, and retesting every two years or after major renovations. Fans eventually wear out and need replacement.
Choosing a contractor
Look for a contractor certified by a national radon proficiency program or licensed by your state if your state licenses radon professionals. Ask about their experience with homes like yours, the warranty on the fan and the system, and whether a post-mitigation test is included.
Radon and home sales
Radon testing is common during home sales. If a test shows high levels, buyers and sellers often negotiate who pays for mitigation. Having an existing system with recent test results can make a sale go smoothly. If you install a system, keep the paperwork and test results, and include them when you sell. Buyers usually want to see a post-mitigation test showing the level is below the action level.
Radon fans and electricity
The fan runs all the time, so it adds a small, steady amount to your electric bill. Fans are usually mounted outside or in an attic, not in living space, so any noise stays out of the rooms you use. Ask the contractor which fan model they plan to use and how long its warranty lasts, since the fan is the part most likely to need replacing over the life of the system.