fitting

States that to be effective, insulation must be installed correctly. Studies have shown that even small imperfections in how insulation is installed will significantly reduce its performance. There are problems associated with the settlement of loose fill insulation, and batt insulation can also sag and create voids - especially if they are not the full depth of the wall, of if they are narrower than the framing space into which they are put. Insulation installers usually work on a piecework basis, so have an incentive to cut corners.