The experiencing on faced insulation functions for a vapor retardant. If you want a vapor barrier as well as your insulation is unfaced, you must protect it with a polyethylene movie. Manufacturers generally connect a experiencing (which include kraft paper, foil-kraft paper, or vinyl) to work as a vapor barrier https://floor-insulation40471.activablog.com/32966644/an-unbiased-view-of-cieling-insulation