America's most common insulation vs. America's healthiest. An honest, data-backed comparison across 8 performance categories — so you can make the right choice for your home and family.
Fiberglass is cheap upfront but costs more over time. GaiaCrete® costs more to install once — then lasts 100+ years with zero maintenance, zero mold, zero VOCs, and 30-50% lower energy bills.
🏆 WINNER
Superior in 7 of 8 categories. The clear upgrade from fiberglass.
RUNNER UP
Only advantage is upfront cost. Degrades, traps mold, and off-gasses for its entire lifespan.
| Metric | GaiaCrete® | Fiberglass |
|---|---|---|
| R-Value/Inch | R-3.5–5.0 | R-3.1–3.7 |
| Mold Resistance | Impossible (pH 12.4) | Mold in 24-48hrs |
| VOC Off-Gassing | Zero — absorbs CO₂ | Formaldehyde binders |
| Fire Rating | 4+ hrs, no chemicals | Melts at high temp |
| Lifespan | 100+ years | 15-20 years |
| Thermal Mass | Excellent | None |
| Energy Savings | 30-50% | 10-15% |
| Pest Resistance | pH 12.4 deters all pests | Rodents nest in it |
| Carbon Footprint | Negative (−112 kg CO₂e/m³) | High positive |
| Installed Cost | $180–360+/sqft | $1-3/sqft |
| 100-Year Cost | One-time investment | 5-6 replacements |
Every claim is backed by lab-verified data. See full GaiaCrete® specifications →
Zero VOCs, naturally antibacterial (pH 12.4). Actively improves indoor air quality by absorbing CO₂. Safe to handle without protective equipment.
Contains microscopic glass fibers causing skin, eye, and lung irritation. IARC-classified possible carcinogen. Many products contain formaldehyde binders. Requires PPE for installation.
4+ hour fire rating without chemical retardants. Chars slowly — does not combust, melt, or produce toxic fumes.
Glass fibers don't burn but paper/foil backing ignites. Melts at high temperatures, losing all insulating value. Does not prevent fire spread through walls.
Permanently mold-proof (pH 12.4). Vapor-permeable — breathes and regulates humidity naturally between 40-60% RH. No vapor barrier needed.
Absorbs and retains moisture. Creates ideal conditions for mold colonization within 24-48 hours. Loses all R-value when wet.
Carbon negative (−112 kg CO₂e/m³). Made from renewable hemp + lime. 100% biodegradable. Sequesters CO₂ for decades.
Energy-intensive manufacturing (melting glass at 2,500°F). Non-biodegradable. Contains formaldehyde binders. Landfill waste.
R-3.5–5.0/inch depending on GaiaCrete® blend. Exceptional thermal mass stores and releases heat slowly — reduces HVAC cycling 30-50%.
R-3.1–3.7/inch. No thermal mass. Temperature swings require more HVAC cycling. Settles over time, reducing effective R-value.
100+ year lifespan. Lime binder strengthens over time through carbonation. Zero maintenance required.
15-20 year effective lifespan. Settles, compresses, and degrades. Rodents and pests commonly nest in it.
Higher initial investment ($180–$360+/sq ft for completed wall assemblies). Premium product, one-time purchase.
Low upfront cost ($0.50–1.50/sq ft installed). Must be replaced every 15-20 years.
Naturally pest-resistant. pH 12.4 alkalinity deters rodents, insects, and termites permanently.
Rodents, insects, and birds commonly nest in fiberglass. No natural pest deterrent. Pest damage requires full replacement.
Take our free 5-minute Healthy Home Assessment to scan for mold risk, VOC exposure, and insulation problems hiding behind your drywall.
GaiaCrete® is the right choice when any of these factors matter to your project:
Build with GaiaCrete® from the start for permanent mold prevention, zero-VOC air quality, and a 100+ year insulation envelope.
Replacing old fiberglass? Upgrade to GaiaCrete® spray-applied insulation for monolithic, seamless wall coverage.
GaiaBlocs™ can be installed in existing wall cavities without full demolition — the easiest path to healthier walls.
Children, allergy sufferers, and chemically sensitive individuals benefit most from zero-VOC, mold-proof walls.
Fiberglass fails fastest in humidity. GaiaCrete® breathes naturally and prevents mold permanently in any climate.
If you plan to own your home for 10+ years, GaiaCrete®'s one-time cost beats fiberglass replacement cycles.
GaiaCrete® outperforms fiberglass in 7 of 8 categories including health (zero VOCs vs glass fiber irritation), fire safety (4+ hour rating vs melting), mold resistance (pH 12.4 vs mold in 24-48 hours), and lifespan (100+ years vs 15-20 years). Fiberglass only wins on upfront cost.
GaiaCrete® costs $180–$360+ per square foot for completed wall assemblies vs $1-3/sq ft for fiberglass installed. However, fiberglass must be replaced every 15-20 years (5-6 times over 100 years), while GaiaCrete® is a one-time investment lasting 100+ years with zero maintenance.
Fiberglass contains microscopic glass fibers that cause skin, eye, and respiratory irritation. The IARC has classified glass fibers as a possible carcinogen. Many fiberglass products also contain formaldehyde binders that off-gas into indoor air.
Yes. GaiaBlocs™ are designed specifically for retrofitting existing homes — they can be installed in wall cavities without full demolition. For gut renovations, GaiaCrete® spray-applied insulation provides complete monolithic wall coverage.
GaiaCrete® is permanently mold-proof due to its pH 12.4 alkalinity — mold cannot grow at pH levels above 10. Fiberglass absorbs moisture and creates ideal conditions for mold, which can colonize within 24-48 hours of water exposure.
Compare GaiaCrete® to other insulation types or explore our products and services.
Stop breathing glass fibers. Start breathing clean air. Get a free GaiaCrete® consultation — we serve all 50 states.
Ranking the safest insulation materials
Read MoreSide-by-side comparison of performance & safety
Read MoreHow pH 12+ walls eliminate mold permanently
Read MoreVOCs, off-gassing & what's in your walls
Read MoreSchedule a consultation or take our assessment to learn how we can help.