Removing Radon from the Home

House/room pressurization. With this method, a fan blows air into the basement from either upstairs or outdoors to create enough basement air pressure to prevent radon from entering. To keep that pressure, doors and windows at the lowest level should remain closed except for normal entry and exit. With this method, more outdoor air enters to dilute interior air, but along with it comes increased moisture. Forced ventilation. This method is similar to house/room ventilation. It uses fans to increase a home's natural air exchange by drawing air into the house. As the existing indoor air leaves the house through vents or open windows, it takes the radon with it. Heat loss can be a problem during cold weather, so this technique should be considered carefully. A heat-recovery ventilator, or air-to-air heat exchanger, is an option. It uses exhausted air to warm or cool incoming air. A heat exchanger is most effective for basement use. It must be properly maintained and can add to energy costs. Sub-slab depressurization. This approach is the most common method for radon mitigation. It generally runs $1,000-$1,500, depending on the local market, how complicated it is to run the pipe(s), and makeup of the underlying soil. The system involves: Installing vent pipe(s) from the subsoil or crushed rock layer beneath the basement floor or slab to an exhaust point above the eave or roof. An electric vent fan not located in or below a livable area. Properly joined and sealed fittings and connections. A warning system that indicates if the fan is not working. A passive system may also be used, relying on natural pressure differences and air currents to draw radon up the pipe and out of the house. The passive system, however, is not considered as effective. Drain-tile suction. This technique uses a continuous loop of perforated tiles around the house perimeter. It can work with an existing drain-tile system to keep water away from the foundation. An exhaust fan is hooked up to the system and the suction created pulls radon away from soil around the house. Sump-hole suction, where the sump pump is capped and serves as the site for a radon-suction pipe, is another option. Crawlspace ventilation. Homes with crawlspaces require additional methods. One is to cover exposed soil in the crawlspace with a barrier, such as concrete or polyethylene. It also may be necessary to vent the radon from under the barrier by pipe and fan to the outdoors. Another option is to use vents in the crawlspace to allow outdoor air to enter or use a fan to blow air across the crawlspace. In cold climates, venting may require insulating affected water lines. Research Radon Contractors Homeowners should consult with a radon specialist about the best mitigation method for their home. Since the EPA closed its proficiency program in 1998, however, there has been no federal certification available. Some states have their own certification programs and others have lists of qualified mitigation specialists. Several states require providers to be licensed or registered. State radon offices can be located at the EPA website. Two independent groups—the National Environmental Health Association (radon.org) and the National Radon Safety Board (nrsb.org) offer national certification programs. Always check references to avoid a ineffectual or dangerous repair. Michael Murphy, health physicist for Region 5 of the EPA, says he has heard about horrendous fixes by unqualified contractors. In one case a dryer-vent hose, which could be easily torn, was used in place of the schedule 40 PVC pipe. Retest after Mitigation After remediation, test to see if the system is working. The test should be conducted within 30 days, but no sooner than 24 hours, after installation to give the system a chance to work. While the contractor may perform a post-mitigation test, a homeowner may want an independent follow-up test. A two- to seven-day measurement is recommended. Contractors may provide a guarantee to adjust or modify the system to reach a negotiated radon level. Retesting every two years will indicate whether a system is still working effectively.

...Continued - Page 2 of 2 ( 1 2 )
< Previous Page