Insulating your attic is one of the smartest ways to improve comfort and lower energy bills. If you’ve narrowed down your choices to cellulose or fiberglass insulation, you might wonder how to finalize your decision. Both have strong selling points, so the best fit comes down to your priorities. Explore how cellulose insulation vs. fiberglass in the attic stacks up in the real world.

Fiberglass batts hold their shape, resist settling, and maintain their insulating value over time. On the other hand, blown-in cellulose can settle and move around, especially if not densely packed to begin with. That doesn’t mean it’s unreliable, but it does demand a skilled installer to ensure long-term performance.

Cellulose insulation is made primarily of recycled paper treated with non-toxic fire retardant. Its high recycled content and low manufacturing energy use make it a top pick for eco-conscious homeowners. Fiberglass isn’t wasteful—often containing recycled glass and sand—but making it requires more energy.

Fiberglass batts are lightweight and easy to install by hand in standard framing. This is the most common choice for quick, budget-friendly projects. In contrast, blown-in cellulose is applied using special equipment. It fills the spaces around pipes, wires, and other obstructions for better coverage and fewer gaps. Cellulose is also great for retrofitting older homes or adding another layer over existing insulation.

Fiberglass doesn’t absorb water, so occasional condensation in the attic won’t bother it. However, because cellulose is made of paper, it soaks up moisture much more readily. This affects performance and leads to mold if things don’t dry out quickly. Some cellulose types are treated to resist moisture, but they still don’t shed water like fiberglass.

Cellulose is denser than fiberglass, making it better at absorbing sound. While wall insulation and tight windows affect noise pollution more than attic insulation, every bit of sound-dampening matters when you live near a highway or have noisy neighbors.

Every home is different, and so are homeowner priorities. Here’s a quick summary to help you decide if cellulose insulation is better than fiberglass or vice versa:

• If you’re looking for insulation you can install and forget about, fiberglass is your best bet.
• If sustainability drives your decision, cellulose earns more points.
• If ease of installation is your goal, fiberglass wins.
• If you have a more complex attic layout or want to add more insulation over an existing layer, cellulose is the right choice.
• If you worry about roof leaks or your attic has poor ventilation, fiberglass is the safest choice.
• If one goal is to maintain peace and quiet, cellulose has the edge over fiberglass.

With years of combined experience and hundreds of happy clients, Titanium Insulation is Chicagoland’s trusted attic insulation contractor. Our highly trained professionals would be happy to recommend cellulose vs. fiberglass insulation based on your situation. As a fully licensed, bonded, and insured company, we strive to always exceed city regulations and guarantee your complete satisfaction. Ready to make your attic better than ever? Contact us today for a free estimate.