Real Estate News

By: Jan Soults Walker

Published: March 25, 2011

Take steps immediately to reduce radon gas buildup if your home tests high. Knowing the available radon mitigation methods and costs will help you make the best choice.

Reducing radon: Simple strategies

If radon test results indicate that levels in your home are only slightly elevated–less than 4 pCi/L (picocuries per liter of air):

• Caulk cracks or gaps in the slab, foundation, or framing–wherever your home contacts soil–to inhibit radon gas infiltration. This step also improves the success of other radon reduction strategies.

• Open exterior crawl space vents to increase air flow and dilute radon buildup.

• Install a heat recovery ventilator (HRV). An HVR introduces fresh, air-conditioned air into homes that are otherwise tightly sealed.

Reducing radon from unsafe levels

If radon levels inside your home test at 4 pCi/L or higher, enlist the services of a professional contractor who is trained in radon mitigation strategies. Contact your state radon office for a list of contractors in your area who are trained and certified in radon reduction techniques. Obtain several bids.

Professional radon mitigation options

Some of the systems used for reducing radon are:

• Soil suction. A special vent fan draws radon from soil beneath your home through pipes that dispel gas into the open. Negative pressure created by the suction further inhibits the buildup of gas. Fans run 24/7, and are usually guaranteed for up to 10 years of continual operation.

• Sub-membrane suction. Considered the most effective strategy for homes with crawl spaces, sub-membrane suction employs a high-density plastic sheet atop the soil. A fan draws radon gas out through vent pipes located beneath the plastic.

• Passive and active ventilation. Ventilating a crawl space or adding additional vents may also reduce radon gas. Opening vents is passive ventilation; adding a fan is active. When employing either of these methods in a colder climate, you may need to add insulation in a crawl space to prevent pipes from freezing.

Costs for radon mitigation

Prices for radon mitigation vary depending on the extent of the work being done, but range between $800 and $2,500. The average cost nationally is $1,200 to $1,400.

As a rule, a house built on a slab or with a basement requires less labor, resulting in the lowest costs for radon reduction. Radon reduction in a house over a crawl space tends to be most expensive since a vapor barrier may be required.

Homes with any combination of slab, crawl space, and/or a basement fall in the middle range for costs.

Another budget consideration: As you ventilate radon gas from your home, energy costs increase—either from releasing air that’s been heated or cooled, or from you operating a fan full-time. Using an HRV to ventilate helps reduce waste.

With four home renovations to her credit, Jan Soults Walker is a devotee of improvements, products, and trends for the home and garden. For 25 years she’s written for a number of national home shelter publications, and has authored 18 books on home improvement and decorating.