Radon mitigation refers to the steps that a homeowner can take to lessen and eliminate the presence of radon gases in a home. It is highly recommended that you have two radon tests performed in order to confirm the radon levels present in your home.
RTCA and Pro-Lab are two sources for inexpensive radon testing kits. Home inspectors and radon measurement specialists can also test for radon levels in a home. The latter options are suggested especially when the testing is part of a real estate transaction. If two or more tests show radon concentrations in excess of the EPAs “action level” of 4.0 pCi/L, mitigation efforts should be made.
This can be accomplished in a number of ways. You can choose passive or active methods depending on the level of effectiveness you are looking for and your budget.
All out active mitigation systems involve the installation of a sub-slab depressurization system which prevents radon from entering the living space. This type of system in an existing home entails creating pits under the slab and connecting them through a network of PVC piping. A fan is installed in one end of the system and is used to force air, and any radon present, safely out of the home at roof level. There are versions available with constant flow as well as ones with level-detection technology. Costs for a system like this vary depending on the size and extent you choose. Estimates are necessary to get an accurate idea of price for your particular situation. $800-$4500 is the typical range.
Less effective passive radon reduction methods can provide a temporary solution but should not be considered a fix. Passive mitigation included opening windows, sealing cracks in the basement floor and placing vent fans in basement windows.
Crawl Space Radon Mitigation
Crawl spaces in homes in high radon areas are especially easy places for radon to enter a home because most have only a dirt or poured concrete floor. The most effective way to prevent radon from coming into the living space through the crawl space is to install a fan at and a vent at the other at floor level. Then cover the entire floor with plastic sheeting making sure to secure it completely to the wall at the edges. This method will capture and expel the radon immediately upon entering the home.
A more passive method of radon litigation for a crawl space would be to only cover the floor with plastic sheeting or just installing the fan/vent system.