July 15, 2024


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What is Fiberglass Loose Fill Insulation?


Insulation is one of the most important facets of an energy-efficient and comfortable home. As such, it is vital you ensure you choose the right insulation. Every home improvement contractor and their dog will have a different opinion on the best type of insulation, but the truth is, what is best is subjective (and usually based on the type of materials the contractor sells). We do things a little differently at Windows on Washington. We base our recommendations on our decades of experience and results.

This article has been published for those researching the best insulation options,  specifically focusing on fiberglass loose fill insulation and everything you need to know about these insulation materials. Ready? Let us dive in.

What is Fiberglass Loose Fill Insulation?

First things first: what is fiberglass loose fill insulation? Fiberglass is a very common and popular insulation material due to the fact it is inexpensive, easy to install, resistant to moisture damage, and non-flammable. You can buy fiberglass pre-shaped as blanket batts and rolls, or you can get loose fill to make your own insulating divisions.

Is Fiberglass Loose Fill Insulation Dangerous?

A common question we are asked about fiberglass loose fill insulation is if it is dangerous. The reality is, fiberglass is a dangerous lung and skin irritant, which is why you should always wear protective gear when handling it. You should never allow your bare skin to come into contact with the material. That is not to say you should avoid fiberglass loose fill insulation, but rather just be extremely cautious, and leave the installation to professional home improvement contractors. 

Is Cellulose Insulation Better than Fiberglass Loose Fill Insulation?

It is important to note that different insulation materials work best in different applications around the home. When it comes to the best insulation for loose fill in attics, we are often asked whether cellulose or fiberglass loose fill insulation is best. 

At WoW, we recommend borate only stabilized cellulose. Why? There are several reasons:

  • Better performance: The R-value of borate stabilized cellulose is much higher compared to loose fiberglass filled insulation.
  • Eco-friendly: Cellulose is made from recycled materials, making it the more eco-friendly choice.
  • Pest-deterrent: In terms of pests, borates are one of the most effective insecticides for your home.
  • No VOC: Borate stabilized cellulose does not contain VOC (volatile organic compounds) content and does not offset gas like ammonium sulfate stabilized cellulose or formaldehyde containing fiberglass does.

Is there a downside to using borate stabilized cellulose? Well, it is often more expensive than fiberglass loose fill insulation, but the benefits of using cellulose over fiberglass make it a worthwhile investment. 

When Should You Choose Fiberglass Insulation?

Fiberglass loose fill insulation is currently dominating the construction housing market. However, builders are currently under enormous pressure to produce a beautiful new home, but at the same time cut costs and stay within a certain budget. Should you completely steer clear of fiberglass insulation? Not necessarily, but you should certainly be aware of the following: 

  • Fiberglass insulation does not effectively protect your home from insects or pests.
  • Fberglass is a skin and lung irritant.

Perhaps the biggest concern when it comes to fiberglass insulation is that it is subject to convective air movement, which means it results in a large degradation of the cumulative R-Value. 

Essentially, it means while you as a homeowner have paid for the Energy Star recommended R-49 in your attic, the real environmental performance of loose fill fiberglass is more like R-25 or less when you need it most.

Why WoW Chooses Cellulose Insulation Instead

At WoW, we believe choosing the right insulation should be based on real-life performance, and not what is most wallet-friendly or what is most popular. That is why we use borate only cellulose for all of our loose-fill insulation projects. Correctly installed cellulose insulation with targeted air sealing will ultimately increase the comfort of your home and drastically reduce your utility bills.

If you need help with your next insulation project, get in touch with the WoW team today for a free quote. 

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