Fiberglass vs. Cellulose Attic Insulation: Pros and Cons

White, spray-in insulation in a new construction.

Insulation is a great way to save energy and money, but how do you choose the right kind? There are many pros and cons to both cellulose and fiberglass insulation. The main ones are as follows:

Pros of Cellulose

  • Cheaper
  • Burns more slowly
  • Made from recycled materials
  • Insulates better

Cons of Cellulose

  • Requires professional installation
  • Messy to install
  • Installed damp, creating a chance for fungal growth if not dried well

Pros of Fiberglass

  • Installed dry
  • Simple to install
  • No harmful chemicals

Cons of Fiberglass

  • More expensive
  • Itchy on your skin
  • Settles, reducing in effectiveness over the years

Although cellulose is made from recycled newspaper, it is not flammable, having been treated with borax. Regardless of which insulation you get, make sure it has the appropriate R-value for your climate zone. The higher the R-value, the stronger—and more expensive—the insulation. R-value will inevitably decrease over time, though, as the insulation settles.

Consider all your options before you decide. Look at your budget as well as the area you are insulating. Then, decide what insulation will be the best investment in the long run.