Cellulose vs Fiberglass Insulation: Which Saves More?

Cellulose vs Fiberglass Insulation: Which Saves More?

Cellulose offers better energy savings long-term despite higher upfront costs, while fiberglass provides immediate savings but may cost more over time due to lower R-values and air leakage issues. Our certified technicians recommend cellulose for maximum energy efficiency and fiberglass for budget-conscious homeowners.

What's the Real Difference Between These Materials?

Dense composition gives cellulose a 20-30% edge in thermal performance over fiberglass -- plus those superior air-blocking capabilities we're always talking about. Made from recycled paper, it creates an airtight barrier that stops energy loss. Fiberglass, while cheaper initially, simply can't match cellulose's density or air-sealing properties.

Here's what you need to know about each material:

Cellulose: The Dense Energy Saver

Cellulose insulation is made from recycled newspaper. Honestly, it's one of the greenest options out there. We treat it with borates (non-toxic minerals) for three key reasons:

1. **Fire protection** - Actually outperforms fiberglass in flame tests

2. **Pest control** - Rodents won't nest in it

3. **Mold resistance** - Stays dry and healthy

Our team recently installed GreenFiber T.A.P.® in a 2,000 sq ft home. That homeowner's energy bills dropped 25% that first winter. Why? Dense-packed cellulose gets into every crack and crevice. No air can sneak through.

Sound familiar? That's because cellulose works like a heavy winter coat -- thick and windproof.

Fiberglass: The Budget Option

Loose-fill fiberglass (think pink Owens Corning or yellow Johns Manville) costs less upfront. That's its main selling point. Here's what our 20+ years of experience tells us:

• **Won't absorb water** - Glass doesn't soak up moisture
• **Naturally fireproof** - Can't burn because it's already glass
• **Lightweight** - Easy to install but easy to blow around

Here's the catch: Air currents reduce its effectiveness. We've seen attic fans literally blow fiberglass away from eaves, leaving homes unprotected.

How Long Does Each Type Last?

Both materials can last 50+ years when properly installed by licensed professionals. However, cellulose settles over time while fiberglass gets displaced by air movement. Quality installation makes or breaks performance -- that's the real difference.

Why Cellulose Settles (And How We Fix It)

Cellulose will settle 10-15% in the first year. That's normal physics. Poor installers just blow in loose material and walk away. We're different.

Our certified technicians use dense-pack installation. This means we calculate exact density to account for settling. Result? Your R-value stays consistent for decades.

What happens with bad installation? We inspected a home last month where cellulose had settled 30%. The owner's cooling bills had doubled. After our team reinstalled it properly, bills dropped 22% the next summer.

The Fiberglass Gap Problem

Fiberglass doesn't settle -- it gets blown around. Strong attic ventilation can create "wind scouring" that leaves bare spots. We've found homes with zero insulation near the eaves because wind blew it all to the center.

How do we prevent this? Proper baffles and careful installation. You can't rush this work.

Real-World Performance: What We Actually See

Last year, we tested two identical homes -- one with each material. Both were installed 15 years ago. Here's what our thermal imaging found:

• **Cellulose home**: Consistent coverage, minor settling
• **Fiberglass home**: 40% coverage loss near vents, multiple cold spots

The cellulose house used 18% less energy that winter.

What's the True Cost Difference?

Fiberglass costs 15-25% less initially, but cellulose typically pays for itself within 3-5 years through energy savings. According to EPA research, proper insulation can reduce heating/cooling costs by 15-30%.

For R-49 in a 1,000 sq ft attic, expect these costs:

**Fiberglass Installation:**

• Material depth needed: 16-18 inches
• Cost range: $1.80 - $2.50 per sq ft
• Pros: Lower upfront cost
• Cons: Higher long-term energy bills

**Cellulose Installation:**

• Material depth needed: 13-14 inches
• Cost range: $2.10 - $3.00 per sq ft
• Pros: Better energy savings
• Cons: Higher initial investment

What's the catch with cheap fiberglass jobs? They skip air sealing. That's like installing windows without weather stripping -- pointless.

How Do You Calculate Real Savings?

Here's a simple example. A typical home spends $1,800 yearly on heating/cooling. Cellulose might save 20% ($360/year) while fiberglass saves 12% ($216/year). That $200 extra for cellulose pays for itself in 18 months.

What Should You Look for in a Professional?

Our team follows strict standards that separate pros from amateurs. Don't hire anyone who won't guarantee these basics:

Non-Negotiable Requirements:

1. **Air sealing first** - Must seal gaps before insulation

2. **Proper density calculation** - Can't just blow and go

3. **Warranty coverage** - Minimum 5-year performance guarantee

4. **Licensed and insured** - Background-checked technicians only

5. **Energy audit included** - Should test before and after

Questions to Ask Every Contractor:

**"How do you calculate proper density?"**

Good answer: We use manufacturer specs and adjust for your climate zone.

Bad answer: We just blow it in until it looks right.

**"Do you seal air leaks first?"**

Good answer: Yes, we seal all penetrations with appropriate materials.

Bad answer: The insulation will stop air leaks.

Honestly? Most contractors skip air sealing. That's where real energy loss happens. It's like trying to heat a house with open windows.

Warning Signs of Poor Installation:

• Quotes significantly below market rate
• Won't provide density specifications
• Rushes through the job in under 4 hours
• Doesn't include cleanup in quote
• Can't explain R-value calculations

Look, here's the thing -- insulation isn't just about throwing material in your attic. It's a system. Air sealing + proper installation + quality materials = energy savings. Miss any part and you're wasting money.

Our certified team treats every job like it's our own home. Because frankly, your comfort and energy bills depend on getting this right the first time.