CAN ONE FIX THE PROBLEM?
-Radon in soil is drawn indoors by the differential between the relatively low air pressure in the house and the higher air pressure in the soil. Therefore, radon reduction strategies fall into two basic categories: those that prevent the entry of radon gas into the home, and those that attempt to remove the radon once it has entered the home. In most situations, the first approach -- preventing radon entry -- is the most effective.
-Although sealing cracks and other openings in the foundation is a basic part of most approaches to radon reduction, sealing alone is not recommended; it is best done in conjunction with other mitigation techniques to enhance their effectiveness.
-The most popular radon mitigation technology is called "sub-slab depressurization" or "sub-slab suction". The "sub-slab depressurization" technique removes radon-laden air from beneath the foundation and vents it outside the house by installing a fan and inserting a pipe through the foundation into the aggregate below, running it to a point outside the shell of the house.
-A similar technique, "sub-membrane depressurization," which is effective in buildings with earth-floored crawlspaces or basements, uses a plastic barrier over the soil as a collection cover. Another depressurization technique for preventing radon entry, "blockwall depressurization," uses a fan and duct work to draw suction on the hollow interior cavities of a concrete block wall. By keeping the air pressure within the block wall lower than the air pressure in the basement, the soil gas is removed before it can enter the basement.
-Reducing radon levels requires technical knowledge and special skills. The EPA operated a Radon Contractor Proficiency (RCP) Program that evaluated radon reduction contractors until 1998. Find out how to find a "qualified" radon service professional at www.epa.gov/radon/radontest.html.
-Selecting a radon contractor is much like choosing a contractor for other home repairs; it makes sense to get references and more than one estimate. The average cost to correct a radon problem in a home is about $1,300, although it can range from about $1,300 to about $2,500. You can order a free copy of A Consumer's Guide to Radon Reduction (see our publications page on how to order). People who choose to fix their homes themselves should refer to the EPA's technical guide, Radon Reduction Techniques for Detached Houses.
-After the radon reduction procedure is complete, the home should be retested. Most radon reduction systems include a monitor that will alert the homeowner if the system needs servicing.
