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 can last 20 to 30 years or more if properly installed and maintained.
To cut fiberglass insulation, use a sharp utility knife and a straightedge to ensure a clean, straight cut.