Spray polyurethane foam is better than any other type of insulation for reducing air leakage, and it's high R-value doesn't diminish.
All About Spray Foam Polyurethane Insulation, Profoam
Why Spray Foam Insulation Is the Superior Insulation Choice
Open Cell Vs Closed Cell Foam Colorado - Ascend Construction
Open vs. closed cell foam insulation - Gable Building
What R-value Do I Need?
Spray Foam R-Value Legend
Spray Foam Insulation: Natural Polymers
Petition · Building Codes: Make the Spray Foam R-Values
What is Spray Foam And What Are Its Benefits?
Understanding R-Values - Tiger Foam Insulation
Touch 'n Foam System 600 Spray Foam Insulation Kit
Cost to Install Spray Foam Insulation
Touch 'N Foam Professional® Wall & Cavity Foam
Open Cell Foam Insulation in McKinney, TX
Spray Foam Insulation Company in Delaware Valley