Why Remove the Old Insulation?

Insulation that exists on the floor of the attic ceiling and any vapor retarder on the floor of the ceiling should be removed to allow for heat and moisture transfer through the ceiling. This is how the unvented attic space becomes indirectly conditioned space and the temperature and humidity in the attic can be controlled. By removing the existing insulation on the ceiling of the attic, you can be ensured that the unvented attic will provide the energy performance     improvements intended by your insulation upgrade.