In large commercial structures, moisture filled air migrates into the environment from the outside climate. The moisture can migrate far enough into the assembly that it can be cooled down to a dew point, at which time the water vapor turns to liquid water. This liquid water corrodes metal in the building assembly, as well as degrading the structural integrity. The Mar-flex Air Barrier 1200 system is designed to stop air infiltration and exfiltration in the building envelope while allowing the transmission of water vapor preventing condensation in the wall assembly. Check out our selection of vapor barriers and air barriers today!