Doesn cellulose insulation settle over time, leaving my walls under-insulated?
Cellulose is a great insulation material that has been used in residences since the 1930’s. Made of recycled newspaper, it provides an excellent thermal barrier while staying one of the most environmentally friendly insulation materials available, and it is fire, mold, and pest resistant. Dense-packed cellulose (meaning about 3.5 pounds of material per cubic foot of volume) can also act as a very effective air barrier. During the 70’s and 80’s, cellulose developed a slightly damaged reputation for “settling” over time—that is, the material in the wall cavity appeared to sink, leaving uninsulated voids at the top of the cavity. Today’s cellulose is manufactured by breaking recycled newspaper down into a fibrous material, which interlocks as it’s blown or sprayed into a cavity, providing much more effective coverage. In addition, the cellulose is (or should be) packed into the cavities at a higher density; the wall or ceiling is actually under a slight pressure from the amount of materia
