Cellulose Insulation
Cellulose insulation is an environmentally friendly option made primarily from recycled paper products treated with fire-retardant chemicals, providing effective thermal and acoustic insulation for buildings.
Composition
Material designed to reduce heat transfer with specific thermal resistance properties
Properties
R-Value
R-3.2 to R-3.8 per inch
Provides good thermal resistance comparable to fiberglass but with better performance in preventing air movement.
Density
2.2 to 3.0 lb/ft³
Higher density than fiberglass, helping to reduce air movement and improve performance.
Fire Resistance
Class 1 Fire Rating
Fire retardant chemicals make it resistant to flame spread, often charring rather than burning.
Sound Absorption
NRC 0.80-0.95
Excellent sound absorption properties due to its density and fibrous structure.
Moisture Handling
Moderate
Can absorb and release moisture, but borate treatments help resist mold and mildew growth.
Settling
5-20% over time
May settle over time, particularly in wall cavities, potentially reducing effectiveness.
Applications
Attic Insulation
Blown as loose-fill insulation across attic floors, providing an even blanket of insulation that conforms around obstructions.
Wall Cavity Insulation
Dense-packed into enclosed wall cavities in both new construction (with netting) and retrofits through holes that are later patched.
Sound Insulation
Installed in interior walls, floors, and ceilings to reduce sound transmission between rooms or floors.
Cathedral Ceiling Insulation
Dense-packed into cathedral ceiling cavities where space is limited and maximum R-value per inch is desired.
Retrofitting Existing Homes
Particularly suitable for adding insulation to existing homes without removing drywall, by blowing into cavities through small access holes.
Floor Insulation
Installed between floor joists over unconditioned spaces like crawl spaces or unheated basements.
Advantages
- High recycled content (typically 85-90%) makes it one of the most environmentally friendly insulation options
- Excellent at filling irregular spaces and conforming around obstacles
- Good sound absorption properties
- Fire retardant chemicals provide good fire resistance
- Less irritating to install than fiberglass
- Effectively fills small gaps and cracks, reducing air infiltration
- Lower embodied energy than many other insulation types
- Pest resistant due to borate treatment
Limitations
- Can settle over time, particularly in wall applications, potentially reducing R-value
- Absorbs moisture more readily than some synthetic insulations
- Requires professional installation equipment for proper application
- Heavier than fiberglass, potentially adding weight to structures
- Dust during installation requires proper respiratory protection
- Not suitable for areas with direct water exposure
- May corrode certain metals if moisture is present
- Requires proper installation density to achieve rated performance
Sustainability Profile
Insulation materials significantly reduce building energy consumption over their lifetime, often offsetting their production impact. Bio-based insulation options offer renewable alternatives to synthetic materials.