Evaluation of house-based remedial measures for limiting soil gas entry

House-based remedial measures to prevent soil gas infiltration have been implemented on many buildings affected by intrusion of radon, water vapor, methane, and other volatile organics (VOCs). The success of these measures has been well documented for gases such as radon; however similar detailed documentation was not readily available for methane or other VOCs. The objective of this study was to evaluate the effectiveness of four different remedial measures installed on houses. The four different remedial measures which were evaluated included: a liner with a subslab passive vent system, an active venting system, a passive venting system, and a liner system only. None of the houses monitored were found to have significant methane indoors due to soil gas entry. Short-term tracer tests were carried out on one of the system to evaluate the integrity of the remedial measure. Based on a limited number of houses tested, the results suggested that the amount of gas potentially entering the house could be limited by as much as four orders of magnitude.