Vapor Barrier Film: Complete Buying Guide 2026
Vapor barrier film is a polyethylene sheet that prevents moisture migration through floors, walls, and crawl spaces. In crawl space encapsulation, 20-mil reinforced poly creates a sealed moisture barrier that dramatically reduces humidity and mold risk. In 2026, vapor barrier film prices average $0.15 per sq ft, with a typical range of $0.08 to $0.30 depending on your region, supplier relationships, and order quantity.
When budgeting for a project using vapor barrier film, factor in approximately 10% additional material for waste, plus labor costs averaging $0.20 per sq ft for professional installation. A typical project using this material runs approximately $650 including both materials and labor.
With an expected lifespan of 50 years, vapor barrier film represents a cost of approximately $0.00 per sq ft per year of service life. This exceptional longevity makes it one of the most cost-effective materials when measured over its full lifespan.