Fiberglass vs. Cellulose: Choosing the Right Insulation for Your Home

When it comes to improving energy efficiency, comfort, and indoor air quality, insulation plays a critical role. But with so many types of insulation for homes available today, choosing the right material can feel overwhelming. Two of the most commonly compared options are fiberglass and cellulose. If you’re asking yourself, “Is cellulose or fiberglass insulation better for my home?”—you’re not alone.

In this guide, we’ll break down the difference between cellulose and fiberglass insulation, compare their pros and cons, and explain why fiberglass remains one of the most trusted and effective insulation materials available—especially when installed by the experts at Complete Insulation.

Understanding the Basics: Fiberglass vs. Cellulose Insulation

Before we dig into performance, let’s define the two materials:

• Fiberglass Insulation is made from extremely fine glass fibers and is typically found in batts, rolls, or loose-fill form. It’s widely used in attics, walls, crawl spaces, and floors.
• Cellulose Insulation is made primarily from recycled paper products treated with fire-retardant chemicals. It’s usually installed as loose-fill, often blown into attics or dense-packed into wall cavities.

While both materials aim to slow the transfer of heat, there are important distinctions that can make or break your home’s comfort and energy performance.

Cellulose Insulation Pros and Cons

Cellulose has gained popularity for its recycled content and ease of installation in certain applications, but it’s not without its drawbacks. Let’s take a closer look:

Pros

• Eco-Friendly: Made from 80–85% recycled paper, cellulose is often marketed as a green option.
• Good Airflow Resistance: It can reduce air movement when densely packed into walls.
• Decent Thermal Performance: Offers R-values comparable to fiberglass (typically R-3.2 to R-3.8 per inch).

Cons

• Moisture Absorption: Cellulose is prone to absorbing moisture, which can lead to clumping, mold, and reduced effectiveness over time.
• Settling Over Time: Cellulose insulation often settles, which can lead to gaps and reduced thermal protection in the long run.
• Dust and Air Quality Concerns: The dust generated during installation or disturbance can impact indoor air quality.
• Flammability Risk: While treated with fire-retardants, it is still made of paper and may pose higher risks in the event of a fire.

Because of these limitations, cellulose insulation pros and cons must be carefully weighed—especially in humid climates or areas prone to moisture intrusion, such as crawl spaces and attics.

The Advantages of Fiberglass Insulation

Fiberglass has stood the test of time for decades, and for good reason. At Complete Insulation, we recommend and install fiberglass because it delivers consistent, long-lasting performance without many of the drawbacks associated with cellulose.

Why Homeowners Prefer Fiberglass

Tennessee homeowners prefer the advantages of fiberglass insulation because of its:

• Durability: Fiberglass does not settle over time, which means it maintains its R-value and effectiveness for years.
• Moisture Resistance: It resists moisture and mold growth better than cellulose, making it ideal for humid regions like Tennessee.
• Safe Indoor Air Quality: Today’s fiberglass is manufactured to be low-dust and formaldehyde-free.
• Cost-Effective: Offers excellent value for performance, particularly in large areas like attics.
• Easy to Install: Whether you’re using batts or loose-fill, fiberglass adapts well to various spaces.

If you’re comparing fiberglass vs. cellulose insulation, fiberglass wins in nearly every category that matters to long-term home performance.

What’s the Best Insulation for Attic Spaces?

When it comes to selecting the best insulation for attic applications, both fiberglass and cellulose are frequently used. However, fiberglass is often the better long-term choice due to its resistance to settling and moisture damage.

At Complete Insulation, we install blown-in fiberglass insulation in attic spaces to help seal gaps, improve energy efficiency, and regulate indoor temperatures. Unlike cellulose, it won’t break down or become compacted over time, giving homeowners lasting protection from heat gain and loss.

For homeowners seeking an even higher-performing product, we also offer spray foam insulation, which provides superior air sealing and thermal resistance. It’s ideal for sealing attics, crawl spaces, rim joists, and other hard-to-insulate areas.

Fiberglass vs. Cellulose Insulation: Which One Is Right for You?

While both fiberglass and cellulose offer similar R-values, their long-term performance differs significantly.

• Fiberglass insulation is moisture-resistant, doesn’t settle over time, and resists mold—making it ideal for Tennessee’s climate. It’s also low-dust, safe for indoor air, and maintains its thermal performance for decades.
• Cellulose insulation, made from recycled paper, is prone to absorbing moisture, which can lead to mold, settling, and reduced effectiveness. It also creates more dust during installation, which may affect air quality.

If you’re choosing between cellulose or fiberglass insulation, fiberglass is the more durable, cleaner, and reliable option—especially when installed by professionals like Complete Insulation.

Talk to Tennessee’s Insulation Experts

At Complete Insulation, we’ve helped thousands of homeowners upgrade their comfort and energy efficiency through smart insulation solutions. While we do not install cellulose, we specialize in fiberglass insulation and spray foam insulation, which offer the best performance for the region’s climate.

Whether you’re insulating a new home or replacing outdated materials, our team can help you choose the most effective option based on your home’s layout, goals, and budget. We’ll walk you through the benefits, compare materials, and provide expert installation backed by years of local experience.

Ready to Upgrade Your Home’s Insulation?

Choosing the right insulation can make all the difference in your home’s comfort and efficiency. While cellulose may seem like a budget-friendly option, the long-term advantages of fiberglass are hard to ignore, especially when installed by seasoned professionals.

Contact Complete Insulation today to schedule your free consultation and find out how fiberglass or spray foam insulation can improve your home’s performance. Whether you’re updating your attic, crawl space, or entire home, we’ll help you make the smart choice for lasting comfort and savings.