Do I Need to Remove Old Insulation Before Adding New Attic Insulation?

A worker adding batt insulation to a floor.

Your current attic insulation will form the basis of the additional attic insulation that you are planning to install. The existing insulation’s heavy-duty paper barrier will act as a moisture barrier for the newer insulation, so you must keep the older insulation in place, especially if there is nothing wrong with it. Yes, fiberglass does settle with age, but it takes years for this to happen, and it still does not lose its insulating qualities. Therefore, unless it is damaged or your roof is damaged, you should not have to remove the original insulation.