Fiberglass Vs. Cellulose Loose-Fill Insulation


Are you looking for the quickest solution to create a more comfortable, energy-efficient, and insulated home? Blown-in insulation could be your answer. Having proper insulation levels in the attic is one of the easiest and most affordable ways to reduce energy loss and save up to 15% on your home’s heating and cooling bills! So, you are ready to insulate your attic, but which type of loose-fill insulation will give the best results?


R-value is the measurement of the insulation’s resistance to heat flow. Fiberglass and cellulose work through conduction, which means heat moves through the material they are made of. This is important when comparing the composition of the two types of blown-in insulation.


You get what you pay for when it comes to cellulose. This insulation is the cheapest of all loose fill options, but here is what you need to know about what you might be putting in your attic. Cellulose is at a lower price point because it is made up of cut up pieces of recycled newspaper material. Manufacturers then add chemicals like boric acid, sodium borate (borax), and ammonium sulfate to make it fire retardant and rodent resistant. These elements can be harmful if exposed through a cut or scrape. In addition, cellulose is still more flammable than fiberglass even after chemical treatment. Although the R-value works as effectively as fiberglass at first, this type of loose fill insulation settles quicker, leaving your attic with less R-value. Your family and your home deserve quality insulation that will last a lifetime!


Fiberglass insulation can help achieve more stable home temperatures for longer without breaking the bank. Primary Home Improvement uses premium fiberglass insulation, and it will not change from its intended R-value over its lifetime or settle in your attic. Premium fiberglass is made up of wool insulation that is an unbonded, virgin fibrous glass blowing insulation made of mostly post-consumer recycled content. Like cellulose, this insulation product is eco-friendly and responsibly manufactured recycled glass.

Unlike cellulose, fiberglass insulation does not require additional fire-retardant chemical treatment due to being non-combustible. This loose-fill option also is validated to be formaldehyde free. This non-combustible element will last for the life of the product, will stop potential fires, and can give peace of mind about possible chemical exposure.

Premium fiberglass insulation is resistant to moisture, fungus, and mold growth. This means that the R-value will not change or sag, preserving thermal performance over time.

If you currently have cellulose in your attic, fiberglass can be blown on top of your cellulose due to its light weight. Cellulose is too dense of a material to be blown on top of fiberglass.

Begin your Insulation Project with a Free Estimate.

Primary Home Improvements can help kick-start your home insulation project.

If you live in the Greater Cleveland area, call 440-610-4792 or request a free estimate appointment for a detailed quote and advice from our Energy Consultants.