Open ground-floor windows on both sides of the house when possible. This can reduce radon levels by circulating air.
Ventilate your home’s crawlspace by installing and keeping open foundation vents.
Seal basement floor cracks with polyurethane caulking.
Keep drain traps moist by pouring water in floor drains once a month.
Obtain a radon test kit. They can be purchased at hardware and home improvement stores.
Some state health departments provide them for free. Follow directions carefully to get accurate results.
If results reveal 4 to 20 picocuries per liter, follow-up testing should be done over the next 12 months. If results reveal 20 to 100 picocuries per liter, another test should be completed in no more than three months.
Hire a qualified professional radon mitigation company if long-term testing (over several months or up to a year) shows radon levels over 4 picocuries per liter. The most common mitigation strategy is subslab depressurization.
The method extends pipes from a permeable layer of gravel or drain tiles below the basement floor, up through the house and through the roof.