Fiberglass Insulation Vs Cellulose Insulation For Attic

Dirty fiberglass batts have a significantly reduced r value.

Fiberglass insulation vs cellulose insulation for attic. Cellulose insulation is also chemically treated to resist fire insects and mold. The two main least expensive and most commonly used residential insulation materials is cellulose and fibreglass. Rather than trying to meticulously lay fiberglass insulation over the attic homeowners and builders can simply blow cellulose insulation throughout the attic. Cellulose provides better sound insulation than fiberglass i e homes are less noisy with it.

This is called wind washing. Because it is denser than fiberglass cellulose is much more resistant to wind washing. Or 7 inches of cellulose. Many fiberglass installers fluff the fiber with extra air so you don t get as much insulation as you re supposed to.

Assuming your current attic insulation is made from fiberglass and has a value of r 13 you d have to add roughly 10 inches of additional fiberglass to hit r 38. This allows the insulation to get into the small pockets and crevices that fiberglass wouldn t be able to. You can get to the same place with either material. Air moving through a vented attic deposits dirt and dust into fiberglass batts.

It has a better resistance to air flow and prevents the upward movement of air caused by temperature differences. Thus creating a more energy efficient home.