Uniform poly film meeting code requirements of an equivalent 6 mil polyethylene sheet. Minimizes the total area needed for ventilation under home. According to code: Except in arid regions with dry soil conditions, a uniform 6-mil polyethylene sheet material or other acceptable vapor barrier material should be installed on the ground surface beneath the home to further reduce moisture. Where an acceptable ground vapor barrier is installed and one such ventilation opening is within 3 feet of each corner of the home, the total area of ventilation openings may be reduced to one sq. ft. for every 1,500 sq. ft. of home.