In the third talk from “The Best of VI in ’25,” Glenn Tofani of Geokinetics/Fullterra, discusses the testing methodology he developed to determine the chemical vapor diffusion rates of barriers used to mitigate vapor intrusion into buildings. Glenn also discusses post-construction verification of mitigation systems using Radon as a surrogate.

Key points discussed:

  • Three different types of QA/QC testing for vapor barriers
  • Testing to evaluate chemical compatibility
  • Transmission characteristics of membranes   
    • Measured since the 1980s
    • Minimum test period is 120, some samples run for years
  • Smoke testing
    • A critical test to reduce the number of leaks
  • Post installation testing to establish soil gas attenuation rates for the membrane
    • Proper installation is critical!