Cellulose vs Fiberglass Insulation: Which Option is Right for You?

Cellulose vs Fiberglass Insulation: Which Option is Right for You?

Deciding between cellulose and fiberglass insulation? At Koala Insulation of Boulder, we understand that choosing the right insulation for your home can be challenging. This article breaks down the pros and cons of each to help you make an informed decision and select the best option for your home.

Key Takeaways

• Fiberglass insulation offers affordability, ease of installation, and durability, but requires careful installation to avoid gaps and voids. It provides higher R-values in the same cavity compared to cellulose.
• Cellulose insulation, made primarily from recycled paper products, boasts superior thermal performance and environmental benefits. However, it can settle over time, which may reduce its effectiveness.
• Cellulose has a somewhat smaller environmental footprint & is non-combustible and better for sound dampening.  Also, keep in mind that fiberglass today is made of over 90% recycled plastic materials. 

Understanding Fiberglass Insulation

Fiberglass insulation, renowned for its affordability and effectiveness, is a preferred choice among many homeowners. Composed primarily of sand and recycled glass, this material makes use of tiny woven glass fibers, constituting about 20% of its content. Variants of fiberglass insulation include:

• blanket batts
• rolls
• blown-in loose fill
• rigid boards
• duct insulation

Each variant offers a different R-value.

The two most prevalent forms of home insulation are fiberglass batts and loose-fill fiberglass, the latter being ideal for attic insulation. Familiarizing oneself with these types can aid in deciding the most suitable option for your home.

Fiberglass Batts

Fiberglass batts, also known as batt insulation, are large sheets of fiberglass that are rolled up and held together by the intertangled fibers and sometimes w/ kraft-facing adhesive paper. These materials are commonly used for insulation in buildings. Here are some key features of fiberglass batts:

• They are designed to fit between standard-sized joists, making installation quick and convenient.
• They are commonly used in wall cavities and attics.
• However, their pre-cut nature can be a drawback in attics with pipes or other obstructions, as customizing them for different shapes can be difficult.   It is important to select a contractor who gives the cuts required for installing batt the correct amount of attention.

Additionally, fitting fiberglass batts around oddly shaped nooks and corners due to electrical conduits, piping, and plumbing can result in voids and other ‘leaks’ that compromise the overall performance of the insulation. Despite these challenges, fiberglass batts remain a popular choice due to their ease of installation and cost-effectiveness.

Loose-Fill Fiberglass

Loose-fill fiberglass insulation, also known as blown-in insulation or loose fill insulation, is installed using a specialized insulation blowing machine. This method is particularly useful for insulating attics and other spaces where batts cannot be easily installed due to obstructions. The loose fibers are blown into place, forming an effective air barrier by packing into cracks and crevices during installation.

One of the main advantages of loose-fill fiberglass is its ability to provide uniform coverage, even in areas with many obstacles. However, it requires professional installation, which can add to the overall cost. Despite this, its effectiveness in reducing air leaks makes it a worthwhile investment for many homeowners.

Pros and Cons of Fiberglass Insulation

Fiberglass insulation offers several advantages, including:

• Affordability
• Ease of installation
• Effectiveness in protecting against poor insulation
• Longer-lasting, safer, and more efficient than many other insulation materials
• Can attain higher R-values in the same wall cavity compared to cellulose, making it a more energy-efficient choice.

Nevertheless, fiberglass insulation also has some disadvantages. Installation can be challenging in areas with numerous obstructions, and if not installed properly, voids can form, reducing its effectiveness. Still, many homeowners choose fiberglass for its overall performance and cost-effectiveness.

Understanding Cellulose Insulation

Cellulose insulation is another popular choice, known for its eco-friendliness and superior thermal performance. Made from recycled paper products such as newspapers, magazines, and cardboard, cellulose insulation often includes fire retardants and insect repellents to enhance its safety and durability. It is available in various forms, however it mostly used and sold as loose fill insulation in bags.

There are several ways to install cellulose insulation, making it a versatile option for different types of homes and applications. Its high usage of recyclable materials makes it an environmentally friendly choice for homeowners looking to reduce their carbon footprint.

Blown-In Cellulose

Blown-in cellulose insulation is commonly used in attics, wall cavities, and ceiling joist bays. It is installed using a blowing machine that sprays the insulation material into the required spaces,. This method allows the cellulose to fill gaps and crevices effectively, providing a thorough insulation barrier.

A widely held misunderstanding is that blown-in cellulose and blown-in fiberglass are identical. Although installation methods are similar, there are some key differences between the two:

• Cellulose is prone to settling over time, potentially impacting its long-term performance.
• Fiberglass is less prone to settling and maintains its insulating properties better over time.
• Cellulose is made from recycled materials and is considered more eco-friendly.
• Fiberglass is made from sand and other minerals.

Despite these differences, both blown-in cellulose and blown-in fiberglass are popular choices for insulation due to their thermal performance in regulating hot or cold air.

Pros and Cons of Cellulose Insulation

Cellulose insulation offers superior thermal performance and environmental benefits, thanks to its high recycled content and effective insulating properties. It can help reduce energy bills by providing better thermal resistance compared to some other insulation materials.

Yet, cellulose insulation also has some downsides. Over time, it can settle, potentially reducing its effectiveness. It is essential to install and maintain it properly to ensure it retains its insulating power and delivers long-term benefits.

Comparing Thermal Performance

Thermal performance crucially hinges on the R-value, which quantifies resistance to heat flow, where higher R-values denote greater insulating power. With an R-value per inch of 3.7, cellulose insulation trumps fiberglass (2.2 to 2.7) in terms of thermal resistance.

That said, due to the fact that cellulose settles around 2” over time the initial installed thickness for both cellulose and fiberglass is similar to achieve the same R-Value.  For example, to achieve an R-30 insulation, cellulose will be installed to an initial thickness of 10” before settling to about 9” in a matter of weeks.  For R-30, fiberglass will be installed to 10.375” deep and remain as such over time.

When comparing cellulose vs fiberglass insulation, cellulose insulation’s dense structure allows it to fill spaces more thoroughly, preventing drafts and heat loss. This higher thermal resistance can lead to significant energy savings, making cellulose a slightly more energy-efficient choice compared to fiberglass.

Installation Ease

When it comes to installing fiberglass insulation, it is generally easier to work with than cellulose due to its less dusty nature and the possibility of being installed without specialized equipment.  The dust that comes with installing cellulose creates a good amount of waste on each project.  Fiberglass batts, for example, can be manually placed between joists without the need for a blowing machine, making the process simpler and cleaner.

In contrast, cellulose insulation typically requires a blowing machine for installation and often necessitates two people to operate the equipment. This can add to the complexity and cost of the installation process. Additionally, the heavier weight of cellulose material can make it more challenging to handle and apply.

Fire Safety Considerations

When it comes to fire safety, fiberglass insulation has a distinct advantage. It is naturally non-combustible and does not require additional fire retardants, making it a safer option for home insulation. While fiberglass can melt at very high temperatures, it will not burn, providing a reliable fire resistance barrier.

On the other hand, cellulose insulation is made from recycled paper products, which are naturally flammable. To improve its fire resistance, cellulose insulation is treated with fire-retardant chemicals such as boric acid or ammonium sulfate. These additives enhance the material’s fire resistance by adding a protective layer, reducing the risk of fire spreading.

Environmental Impact

Primarily due to its high recycled content, cellulose insulation has a smaller environmental footprint than fiberglass. That said, manufacturing for both cellulose and fiberglass have come a long way in the last 10-15 years.  Both products are now composed of 85+% recycled materials.

Long-Term Performance

Fiberglass insulation maintains its original form and effectiveness longer than cellulose, which can settle and lose insulating power over time. Properly installed fiberglass insulation does not settle or degrade, ensuring consistent thermal performance over its lifespan.

In contrast, cellulose insulation can compress and reduce its effectiveness due to settling, which can lead to a loss of R-value and increased air transfer. The settling rate of cellulose insulation in open attics is approximately 20 percent, which can significantly impact its long-term performance.

Cost Comparison

Generally, fiberglass insulation is slightly more expensive than cellulose insulation in terms of both material and installation costs. While the underlying material for cellulose is cheaper than fiberglass, due the dust, waste, and difficulty of install that comes with cellulose - customers that work with contractors do not realize the full cost savings due to the need to price in additional waste and labor time.

Choosing the Right Insulation for Your Home

The selection of right insulation for your home hinges on several factors such as thermal performance, ease of installation, cost, and environmental impact. A grasp of the differences between cellulose and fiberglass insulation is key to making an informed decision that aligns with your needs.

For those unsure where to start, consulting with an insulation contractor or taking advantage of free insulation consultations can provide valuable insights and help you choose the most suitable option for your home. Ultimately, the right choice will depend on your specific requirements and priorities, whether it’s maximizing energy efficiency, reducing environmental impact, or minimizing installation costs.

Summary

In summary, both cellulose and fiberglass insulation offer unique benefits and drawbacks. Fiberglass insulation is affordable and easy to install, with excellent fire resistance and long-term performance. On the other hand, cellulose insulation provides superior thermal performance and environmental benefits but may require more careful installation and maintenance to prevent settling.

By understanding these differences, you can make an informed decision that best meets your home’s insulation needs. At Koala Insulation of Boulder, we are here to help you choose the best insulation option for your home. Whether you opt for fiberglass or cellulose, investing in quality insulation with our professional services will enhance your home’s energy efficiency, comfort, and overall value. Contact us today to get started on your insulation project!

Frequently Asked Questions

What is the main difference between cellulose and fiberglass insulation?

The main difference between cellulose and fiberglass insulation is their composition and performance. Cellulose insulation is made from recycled paper products and offers superior thermal performance, while fiberglass insulation, made from glass fibers, is more affordable and easier to install.

Which insulation material is more environmentally friendly?

Cellulose insulation is more environmentally friendly than fiberglass insulation because of its high recycled content (about 85%) and lower carbon footprint. It is a better choice for reducing environmental impact.  That said, modern day fiberglass is composed of around 90% recycled material.

How does the installation process differ between cellulose and fiberglass insulation?

The installation process for the two is virtually identical.

Which insulation provides better fire safety?

Fiberglass insulation provides better fire safety as it is naturally non-combustible, while cellulose insulation requires additional fire-retardant chemicals to enhance its fire resistance. Therefore, when considering fire safety, fiberglass insulation is a better choice.

How do cellulose and fiberglass insulation compare in terms of long-term performance?

Fiberglass insulation maintains its form and insulating power longer than cellulose, which can settle and lose effectiveness over time. Therefore, properly installed fiberglass insulation generally provides better long-term performance.