Spray Foam Insulation
Spray foam insulation is a high-performance insulation and air barrier material that expands upon application to fill cavities, gaps, and hard-to-reach areas, providing superior thermal resistance and air sealing.
Composition
Material designed to reduce heat transfer with specific thermal resistance properties
Properties
R-Value (Closed Cell)
R-6.0 to R-7.0 per inch
Provides high thermal resistance, significantly higher than traditional insulation materials.
R-Value (Open Cell)
R-3.5 to R-3.8 per inch
Lower thermal resistance than closed cell but still effective for many applications.
Density (Closed Cell)
1.75 to 2.25 lb/ft³
Higher density provides structural rigidity and greater moisture resistance.
Density (Open Cell)
0.4 to 0.6 lb/ft³
Lower density allows for greater flexibility and sound absorption.
Air Permeability
Very Low to None
Creates an effective air barrier, significantly reducing air infiltration.
Moisture Resistance (Closed Cell)
Excellent
Acts as a vapor barrier at sufficient thickness (typically >2 inches).
Applications
Wall Cavity Insulation
Sprayed between studs to create a seamless thermal and air barrier in exterior walls.
Attic and Roof Insulation
Applied to the underside of roof decking or between rafters to create conditioned attic spaces or in traditional attic floors.
Rim Joist Sealing
Applied at the junction between foundation and floor framing to prevent air infiltration and insulate a common thermal weak point.
Crawl Space Insulation
Used to insulate and seal crawl spaces, often applied to walls rather than between floor joists to create conditioned crawl spaces.
Basement Wall Insulation
Applied directly to foundation walls to provide continuous insulation without thermal bridges.
Air Sealing
Used to seal penetrations, gaps, and hard-to-reach areas where air leakage occurs.
Advantages
- Highest R-value per inch among commonly used insulation materials (closed cell)
- Creates both an air barrier and insulation in one application
- Conforms to irregular spaces and can fill hard-to-reach areas
- Adds structural strength to walls and roofs (closed cell)
- Excellent moisture resistance (closed cell)
- Doesn't settle or sag over time
- Reduces the need for separate air sealing work
- Long lifespan with minimal degradation of performance
Limitations
- Higher initial cost compared to traditional insulation materials
- Professional installation required with specialized equipment
- Potential for off-gassing during and shortly after installation
- Requires proper ventilation during installation and curing
- Difficult to remove or modify once installed
- Can trap moisture in building materials if water intrusion occurs
- Environmental concerns with blowing agents in some formulations
- Open cell foam requires a separate vapor barrier in cold climates
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.