Two Vapor Barriers and Standing Water in Crawl Space

Tim Hance of All Islands Home Inspections discovered two (2) or more vapor barriers in a crawl space filled with water at a recent Anacortes, WA home inspection. The reason that two (2) or more vapor barriers is frowned upon is because water, if it enters the crawl space, can become entrapped between vapor barriers, prolonging evaporation time and leading to stagnant water conditions. Here in the Pacific NW, water intrusion into a crawl space or basement should be dealt with promptly as it can lead to structural damage/settling and insect activity (e.g., carpenter ants, anobiid beetles and Pacific Dampwood termites are attracted to moist areas). In this particular case, the installation of a perimeter curtain drain was recommended to the clients by a licensed contractor.