Spray foam insulation is made from polyurethane, which expands and hardens to form an insulating barrier.
R21 insulation is approximately 5.5 inches thick. This type of insulation is often used in walls and provides a higher R-value compared to standard insulation options, contributing to improved energy efficiency and thermal comfort in residential and commercial buildings.
Spray foam insulation is ideal for crawl spaces due to its water-repellent properties and resistance to biological growth.