Comparison Between Cellulose Insulation And Fiberglass Insulation

Need to pick between the two and don’t know what’s best for your home? Read our comprehensive guide to get your answer.

 

“So what is better, fiberglass or cellulose?”

We hear this question a lot! To give you an answer, once and for all, we gathered everything you need to know in one place.

Let’s start…

 

Insulation 101

In the days before stricter building codes and safety regulations, builders and homeowners could take their pick from a number of insulation materials: Mineral-Wool, Rock-wool, Fiberglass, Vermiculite, Cellulose and more. As time went on, the options narrowed as one or the other insulation material was found to be impractical, ineffective or just plain dangerous. Today, the two most common, safe and cost-effective options are Cellulose and Fiberglass. Where the confusion begins is that Cellulose is available only in blown material form while Fiberglass can be found in both blown or rolled batting forms. All it takes is a little research to find out which of the two is the better insulation material for your needs.

Fiberglass VS Cellulose

Fiberglass Insulation Material

❏ Made up of sand and recycled material
❏ Can be batts or blown
❏ Most common/cost-effective
❏ Highly effective as thermal insulation
❏ Resists both mildew and mold
❏ Can last 30 years
❏ Often comes with a lifetime warranty
❏ Comes in a range of R-Values
❏ Nonflammable

Cellulose Insulation Material

❏ Made up of recycled newspaper, magazines & cardboard
❏ Itch-free insulation material
❏ Comes in a range of R-Values
❏ Resists insects
❏ Highly effective as thermal insulation
❏ Resists both mildew and mold
❏ Needs just 8.1” to achieve an R-30
❏ Provides soundproofing
❏ Soft material for insulation
❏ Fire-retardant

EFFECTIVENESS

Fiberglass and cellulose are both used for thermal insulation and come in a range of r-values. Fiberglass is quicker to install and offers more protection against mold and mildew growth. It is the most cost-effective and common insulation material today. Cellulose, however, does offer more depth in r-value. It takes 12” thickness or more of Fiberglass to secure an R-30 rating while Cellulose material only requires the thickness to be 8.1” to gain the same R-30 rating. However, Fiberglass is lighter in weight, which makes it easier for it to move through the blow-in pipes and more efficiently cover all the spaces needed in your attic. Cellulose’s heavier material adds more unnecessary weight to your drywall.

LONGEVITY

While Cellulose may provide more depth and better soundproofing qualities, it may lose its r-value over the years. After installation, cellulose has been reported to pack and settle. This can cause it to form pockets in the settled areas which can transfer hot or cold air into your home. Fiberglass, on the other hand, stays in its original form and shape, which typically means it lasts longer. Fiberglass can last over 30 years and often comes with a lifetime warranty. It is also quicker to install and offers more protection against mold and mildew growth.

SAFETY

Fiberglass, which is naturally nonflammable, is made up of sand and other natural/recycled materials, while Cellulose (made up of newspaper; magazines; and cardboard) contains artificial chemicals. This is because when cellulose is bound together to create the insulation material, the machines used are not able to filter everything correctly, leading to pieces of credit cards, plastic cups, and other wasteful products being shredded into the material. Adhesive, boric acid, and stabilizer chemicals are then added to cellulose. The boric acid allows cellulose to provide protection against pests, and also makes cellulose a fire-retardant material. However, Cellulose dissipates over time and turns to dust. The chemicals in Cellulose then become airborne contaminants that enter your home’s air, specifically through light fixtures and electrical ventilation, making the air in your home hazardous to you and your family. Fiberglass, however, uses natural binders and adhesives, making it the healthier, safer and more eco-friendly choice

 

Blown-in Vs. Rolls (Batting)

Batts or rolls made of Fiberglass provide utility since they can be installed under floors or used for open-framing situations or at brand-new construction sites. However, when a home is already built, fiberglass can either be blown with loose-fill (cellulose or fiberglass) material or rolled with batting. Blown application provides more benefits over batting application.

 

Most homeowners work with the assumption that batting is superior since it seems like a neater insulation job. Others are either recommended to think this way due to their contractor or they are just familiar with the rolled form. Rolled fiberglass is installed, in most situations, only because it is more convenient to do so during construction. If anyone takes the time to do some research, it is easy to see that blown Fiberglass would be a better choice.

 

One major disadvantage is how rolled material must be installed between every single ceiling joint, with it being fitted loosely at some points and tightly at others. Rolled material must be fitted around many oddly shaped nooks and corners due to electrical conduits, piping and plumbing in the attic space. Rolled application results in voids and other ‘leaks’ that compromise the overall performance of the insulation. For a tighter, blanket-type insulation, homeowners should opt for blown application or “monolithic fill”. “Monolithic Fill” stands for blown material that is applied in a way that it seals and covers everything in that space like a blanket.

 

Research at the University of Colorado has concluded that R-30 batting is rivaled in performance by blown-in insulation rated at R-19. Flipping this over, R-30 batting only matches R-19 when it comes to practicality. Rolled material may be stamped as R-30 but it delivers a performance of R-19.

 

Attics with existing or old insulation will not work well with rolled material as it leaves gaps and results in a compromised fit. This is the reason why only homes lacking insulation are chosen to be fitted with rolled fiberglass. Removing or vacuuming-out old insulation is an impractical, expensive and time-consuming task. It is better to stack more material on top and bring the attic’s performance up to R-38 or R-30.

 

Since blowing insulation allows installers to “shoot” material up to a distance of 20 feet, they can reach those hard-to-reach spots. Not every inch of the attic needs to be worked upon, so this reduces the chance of disrupting wiring or placing considerable burden upon ceiling framing that may crack under the installers’ weight. Blown material covers the entire attic floor and reaches into the deepest corners with ease.

 

Fiberglass is a better option than cellulose as it is longer-lasting, safer and more cost-effective. Do refer to our materials comparison breakdown for further details.

The Fake News of Insulation

So many homeowners I have had conversations with over the years say they do not want “the blown-in” materials for insulation. The thing to remember is not all blown insulation works the same way. The other reason homeowners avoid blown insulation is that they had it in their previous homes. They confuse blown cellulose for blown fiberglass insulation. While fiberglass will also eventually settle down, it will do so to a lesser degree than blown cellulose and carries a lifetime warranty to retain its insulating qualities.

So Why Do Insulation Companies Still Use Fiberglass?

1. One of the main reasons insulation companies still use fiberglass batts as insulation material is that their primary work is with new construction projects that have requirements for rolled fiberglass. Insulation companies promote and use fiberglass batts as much as possible because the more fiberglass batt products they use, the better and more affordable their purchasing tier becomes.

2. Most insulation companies do not possess the costly equipment for regular installation, like a truck and insulation blowing machine, so they choose to promote rolled Fiberglass instead.

3. The fact that most homeowners shopping for insulation are already familiar with Fiberglass batts helps insulation companies sell it. Homeowners have most likely seen it being installed at new construction sites or on the shelves at a local home improvement store.

Keeping in step with contemporary trends in building and construction, Fiberglass insulation’s popularity is due to it being a superior product- it is longer-lasting, safer, more effective and more efficient than any other insulation material.

In conclusion: in most cases fiberglass blown-in insulation is the superior choice, however fiberglass batt insulation is a suitable candidate for replacing blown-in when required. It is to be said that both materials are far superior to the inferior blown-in cellulose insulation material.

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CALL NOW
(213) 444-5335

 

COMPANY INFO

Insulation Labs
CA Lic. #1034380
Tel: (213) 444-5335
Email: [email protected]

LOCATIONS

7023 Valjean Ave,
Van Nuys, CA 91406

25125 Santa Clara St,
Hayward, CA 94544

1038 E. Bastanchury Rd,
Fullerton, CA 92835

3923 McLaughlin Ave.
Los Angeles, CA 90066

 

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HOURS

Mon-Fri:
7:30am-8:00pm
Sat-Sun:
9:00am-3:00pm