Less than-Slab Insulation: This technique requires positioning insulation materials beneath the concrete slab. Rigid foam insulation boards or spray foam insulation are generally used for below-slab insulation. Manufacturers frequently attach a struggling with (for example kraft paper, foil-kraft paper, or vinyl) to act as a vapor barrier and/or air barrier. https://andyrfxpa.pointblog.net/everything-about-cieling-insulation-77346170