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Fiberglass vs. Cellulose Insulation in Kansas City

Fiberglass vs. Cellulose Insulation: Why You Should Use Fiberglass Insulation in Your Home

As anyone who lives in Kansas City will tell you, our winters can get cold . Like, really cold. Rarely does a winter pass without a few nights getting down to 0°F or lower. To keep your home warm through these chilly day and nighttime temperatures, and to keep your energy bill down, you need quality insulation provided by a Kansas City insulation company—but what’s better, cellulose or fiberglass insulation?

There are a few different options for home insulation materials today, the two most popular of which are fiberglass and cellulose. In recent years, there has been much debate about which type of insulation is the best for Kansas City homes. These two common types of insulation are both great options, but there are distinct pros and cons that you should consider for your next insulation installation.

When it comes to homes in Kansas City, fiberglass insulation is often the better choice. To contribute to the fiberglass vs cellulose debate, we’ve included some advantages of fiberglass that show why it should be a real contender for your home.

What is Fiberglass Insulation?

Insulation materials work by trapping air in thousands of tiny little pockets. Insulation in a warm house will hold on to this warm air, even with cold temperatures on the other side of the wall.

Fiberglass was accidentally invented in the 1930s by Dale Kleist, a researcher at an Ohio glass company. When Kleist attempted to seal two glass blocks together by spraying molten glass, he inadvertently created tiny glass fibers. The fiberglass insulation we know today is the pink, fluffy, cotton candy-like material that we see in many buildings throughout Kansas City.

What is Cellulose Insulation?

Cellulose was around long before fiberglass, but it was rarely used until the 1950s. This is because early cellulose was very flammable. Historically, cellulose was made up of some combination of the following:

• Newspaper
• Cardboard
• Cotton
• Straw
• Sawdust

Today, most cellulose insulation used in Kansas City is made up of at least 75 percent recycled paper or denim. The paper fibers are saturated with a flame retardant, making them safe for use as a type of insulation.

Fiberglass vs. Cellulose Insulation: Advantages and Disadvantages

Determining the best type of insulation isn’t so clear cut. Both insulate Kansas City homes well, so how can you decide which is the superior choice? When looking at fiberglass vs. cellulose, there are several factors you should consider, such as:

Ease of Installation

If you’re planning to install insulation on your own, the ease of installation matters, but it could also affect the overall costs for professional installation too. Your overall installation experience could depend on the form your insulation comes in too. There are several forms of installation, but two of the most common are:    

• Batts are pre-manufactured sheets or rolls of insulation. Because they’re pre-cut, they’re fairly easy to install in wall cavities.
• Blown-in insulation is a loose material that requires a machine to blow it into place. This is the preferred method for small spaces, as it makes it easier to fill small holes and crevices that are hard to insulate with batts.

Because cellulose typically does not come in batts, fiberglass is often the clear winner when it comes to greater ease of installation for walls and other common cavities. 

Soundproofing

To determine the level of soundproofing a material provides, there are two measures you can use: sound transmission class (STC) and the noise reduction coefficient (NRC). The STC is the amount of decibel decrease that occurs when a sound passes through material, and the NRC is the amount of sound that is absorbed by the material. For both measures, the higher the number, the greater the soundproofing.

A standard batt of fiberglass insulation that is 3.5 inches thick has an STC of 39 and an NRC of 0.95. Standard cellulose has an STC of 44 and an NRC of 0.80. Fiberglass therefore has a higher NRC, meaning it absorbs more sound than cellulose, while cellulose has a higher STC, meaning it blocks more decibels from passing though. In the end, that makes them about even when it comes to sound absorption.

These values should also be taken with a grain of salt, as both STC and NRC largely depend on the thickness of the insulation. If you want more soundproofing, all you have to do is add a bit more product. Additionally, because both types of insulation provide fairly good soundproofing, you’ll likely be pleased with the results of fiberglass just as much as you would be with cellulose.

R-Values

R-value is a measurement used to determine insulation performance. Measured per inch, the R-value corresponds to the ability of the insulation to prevent the flow of heat from passing through it, or to prevent air leakage. Thus, the higher the R-value, the greater the energy efficiency—and often, the higher the cost of the insulation.

The United States is broken into 7 regional R-value zones, with zone 1 needing the lowest R-value and zone 7 needing the highest. Each zone has a suggested target R-value for attics, walls, and floors. Kansas City falls between zones 4 and 5, so the ideal target R-values for Kansas City are:

• R38 to R60 for attics
• R13 to R21 for walls
• R25 to R30 for floors and crawl spaces

With these targets in mind, let’s look at the R-values for cellulose and fiberglass. The values will vary somewhat depending on the type of fill and the brand of insulation chosen, but in general, you can expect to see the following:

• R3.2 to R3.8 per square inch of cellulose
• R2.2 to R2.7 per square inch of blown-in fiberglass
• R3.1 to R3.7 per square inch of fiberglass batts.

These values mean that you can meet your needs with both cellulose and fiberglass, but you’ll generally get the best R-value between the two when you choose fiberglass batts over blown-in cellulose.

Moisture

If you had to guess, which type of insulation would you say has a higher water absorption? The paper or the glass? Unless you already knew the answer to this question, you probably said that cellulose absorbs more water. Though it defies logic, you’d be wrong. Although cellulose is largely made from recycled paper, it has been treated not just with a flame retardant, but also a solution that helps it resist decay and moisture.

Unlike cellulose, fiberglass can absorb more water, but due to its composition, even when wet it is very unlikely that any growth of mold will occur. However, prolonged moisture can cause fiberglass to lose some of its air pockets and become compressed, thereby reducing its R-value.

The bottom line? Mold spores are more likely to develop within wet cellulose, but compression is more likely to develop within wet fiberglass. Neither type of insulation really comes out on top—but, unless you’re expecting your insulation to become wet for a very long period of time, this shouldn’t really be a major concern anyway. 

Health Risks

Health-conscious homeowners often wonder if there are any health risks associated with different types of insulation. The short answer? No, your insulation will not impact your health.

That being said, fiberglass insulation can pose a minor health risk to installers. Because fiberglass is made of tiny glass shards, airborne glass fibers can cause some adverse health effects—namely itchy skin and throat irritation. To prevent this, installers will wear a dust mask and gloves to protect their skin and their lungs.

Once installation is complete, there shouldn’t be any significant air movement or air flow. The air quality in your home will therefore remain unaffected by your insulation.

Environment

In a world where being environmentally conscious is increasingly more important, the environmental impact of fiberglass vs cellulose insulation is also worth considering.

Cellulose that is manufactured and used today is significantly treated with one of three solutions: boric acid, borax nitrate, or ammonium sulfate. Though the names of these solutions sound a little scary, all three have very low toxicity to people, animals, and the environment. This insulation type is also made of approximately 80 percent recycled newspaper. Most cellulose is manufactured fairly locally and does not require considerable energy, resulting in a fairly small carbon footprint.

Fiberglass is made from about 20 percent recycled glass and 80 percent sand. It also requires more energy to produce than cellulose. However, the most important consideration to keep in mind when looking at environmental impact is the amount of energy you will save by properly insulating your home. When it comes to that criteria, the higher R-Value of fiberglass batts is the clear winner for energy efficiency.

Cost

A couple factors worth considering for fiberglass vs. cellulose insulation in Kansas City are insulation costs and energy costs. Going for the cheapest insulation options with lower R-values may be less expensive upfront, but over time you’ll end up spending way more money on your energy bills. Conversely, going for the most expensive insulation in Kansas City may give you more insulation than you need and won’t make an impact on your energy bills.

Let’s do a cost comparison of insulation batts for a Kansas City attic. As discussed above, we want a minimum R-value of 38 for a local attic. To determine which type of insulation will be the most cost-effective for you at the time of purchase, compare the cost of the quantity of fiberglass you will need to reach R38, and the cost of the quantity of cellulose insulation you will need to achieve R38.

As a general rule, fiberglass tends to cost less than cellulose. However, the cost of insulation can vary depending on supply chain shortages and various other factors, like the size of your home in Kansas City.

Is Fiberglass Insulation Better in Kansas City?

Based on the factors above, which insulation is better for your Kansas City home? Let’s do a quick overview of the facts.

Pros of Cellulose

• Has a higher STC
• Has a higher R-value vs. blown-in fiberglass
• Uses more recycled material

Cons of Cellulose

• More susceptible to mold
• Has a higher cost
• Has a lower R-value vs. fiberglass batts

Pros of Fiberglass

• Has a higher NRC
• Has a lower cost
• Less susceptible to mold
• Higher overall R-value in batts

Cons of Fiberglass

• Uses less recycled material
• Has a lower R-value in its blown-in form

Both fiberglass and cellulose retain their R-value in all but extreme cold weather (we’re talking even colder than Kansas City gets), and are fairly free of adverse health effects. So, when looking at fiberglass vs cellulose insulation, which one is right for you?

At the end of the day, both fiberglass and cellulose can be installed to give you relatively equal R-values and soundproofing, which are the most important factors for most people in Kansas City. The deciding factors are usually cost and energy efficiency. If you can achieve the same level of comfort and energy efficiency by spending less, why wouldn’t you do so? On this point, fiberglass often comes out on top in Kansas City.

Call Koala Insulation of South Kansas City for Fiberglass Insulation Installation Today

Koala Insulation of South Kansas City is the leading choice for fiberglass insulation installation. You can rely on a Koala Insulation technician to follow proper installation techniques and get your attic, flooring, and walls to the target South Kansas City R-value. To guarantee your satisfaction, we also provide a lifetime warranty on our commercial and residential insulation workmanship.

Still have questions about fiberglass vs cellulose insulation in Kansas City? We’re happy to answer any questions you may have. Whether you’re ready to book an appointment or simply want to discuss your insulation needs, give our professional and friendly team a call at 816-929-8255 or book a free insulation evaluation online. We can’t wait to hear from you!