Crawl Space Vapor Barriers and Encapsulation
Not only are crawl spaces typically located underneath a home where water runoff is more common, but they are also often designed with dirt floors, making them a breeding ground for moisture and mold. Installing a proper vapor barrier or crawl space encapsulation can help in preventing basement moisture.
Installing a sheet of polyurethane as a vapor barrier over the dirt floor can reduce moisture in a crawl space by fifty per cent. Measure the crawlspace before cutting the polyurethane sheet to size. Once cut, pull the vapor barrier tight across the floor - this may require the help of an extra set of hands - and begin securing it along the perimeter of the wall using a staple gun and moisture barrier tape. Encapsulating the crawl space this way makes it air tight.
As an extra precaution keep the polyurethane sheet from getting damaged by covering it with sand.