Blow-In Insulation

Blow-in fiberglass insulation is made from tiny glass fibers and is typically used to fill attic floors, wall cavities, or other hard-to-reach areas. It’s a lightweight material that’s resistant to moisture and mold, and it doesn’t settle much over time. The installation process involves using a machine to blow the loose fiberglass into the desired area, creating a thick, even layer that helps reduce heat loss and improve energy efficiency. Because it’s inorganic, fiberglass is less likely to attract pests and generally maintains its insulating properties for many years.

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Blow-in cellulose insulation, on the other hand, is made from recycled paper products—mostly newsprint—that are treated with fire-retardant chemicals. It has a dense composition that can offer better soundproofing and air sealing compared to fiberglass. Cellulose is also installed using a blowing machine, and it tends to settle slightly over time, which can impact long-term performance if not properly accounted for during installation. The main differences between the two lie in their materials, moisture resistance, fire resistance, and how they settle or hold up over time. Fiberglass resists moisture better, while cellulose generally provides better coverage in small gaps and spaces.