Cellulose Insulation Myths BUSTED! We’re debunking one of the biggest misconceptions in the insulation world: “Cellulose settles too much.” Here’s the truth ⬇️ Greenfiber Cellulose does not settle in walls when it’s installed correctly. Wall spray applications are packed at over 3 lbs per cubic foot, giving it the density needed to stay locked in place permanently. In an attic, cellulose will settle slightly, but only because attics use a different application method. That’s why we install Green