Chlorinated solvents, such as tetrachloroethylene and trichloroethylene, are among the most widespread groundwater and surface-water contaminants in the United States. As the construction industry continues to build larger and deeper buildings into the water table, there is a growing probability that the pre-applied water mitigation systems used in these buildings will be exposed to contaminated groundwater and soils over the course of their service life. Understanding how different membranes and contamination exposure affect the chemical permeation rate is essential to being able to predict the waterproofing's long-term performance as a chemical barrier and ensure indoor air quality is not affected. Using existing standards as a reference, we developed a method to measure the chemical permeation rate of the below-grade waterproofing membranes at different temperature and concentration gradients. This method can accelerate the evaluation process, especially with low-permeable membranes, which typically require longer evaluation times. In addition, this method enables the analyst to build a correlation between chemical permeation rate, temperature, and time. Thus, the method presented herein provides a new way to compare the long-term performance of different membranes and can play an important role in the design of water-mitigation systems for buildings.