Insulation notes
Blown Cellulose Vs. Fiberglass: Which Insulation Is Better for Your Home?
May 25, 2025
Before adding any new insulation, it’s essential to inspect for mold or moisture issues in your attic. Old or compressed insulation, especially in homes with poor ventilation, often hides early signs of mold growth. Left untreated, this can lead to air quality problems, odors, and even structural damage.
At Eco-Therma, we always recommend a professional mold inspection and, if needed, antifungal treatment before proceeding with any insulation upgrade.
We offer eco-friendly mold removers and proven antifungal sprays to sanitize attic surfaces before applying blown insulation—whether it’s cellulose or fiberglass. This ensures your attic is clean, safe, and mold-resistant long-term.
What Is Blown Cellulose Insulation?
Blown cellulose is made from recycled paper fibers treated with fire-retardants and mold inhibitors. It’s blown in to form a dense, seamless layer of insulation.
Pros:
- Eco-friendly and sustainable
- Excellent air sealing
- Superior soundproofing
- High R-value per inch (R-3.2 to R-3.8)
Cons:
- Can absorb moisture if not properly sealed
- May settle slightly over time
What Is Fiberglass Insulation?
Blown fiberglass is made from spun glass fibers and is also installed using a blowing machine.
Pros:
- Budget-friendly
- Moisture resistant
- Non-settling
- Consistent R-value (R-2.7 to R-3.6 per inch, varying with the product, its density and the system)
Cons:
- Less effective at sealing air leaks
- Can leave gaps if not installed carefully
Which One Should You Choose?
Priority, and the recommended insulation:
- Best air sealing: Blown Cellulose
- Budget-conscious: Fiberglass
- Mold-prone areas: Fiberglass (with vapor barrier / Mold Sealant)
- Eco-friendly homes: Blown Cellulose
- Soundproofing: Blown Cellulose
Our Complete Attic Solution
When you choose Eco-Therma, you’re not just getting insulation. You’re getting:
- Full attic mold inspection
- Antifungal spray treatments
- Professional air sealing
- High-quality insulation upgrade
- Before-and-after photos & More
Book Your Free Inspection Today !
Don’t insulate over a problem—fix it first. Book your free attic inspection in Toronto, Mississauga, Vaughan, or anywhere in the GTA and beyond. We’ll guide you through the safest, most energy-efficient option for your home.
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Where this applies
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Who writes these articles?
Eco-Therma writes these articles for Ontario homeowners, about attic conditions the crews see in the field. Each article explains what a material or a condition actually does, rather than selling a product.
Will an article tell me what my attic needs?
An article will help you understand the options and what changes the answer. What your attic needs specifically comes from an Eco-Therma quote on your own address.
Why is there no pricing in the articles?
Because the number would be wrong for most readers. Attic size, existing condition, access and the work required all move it, so we explain what changes the price and quote the actual project.
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