Foam board insulation is a type of rigid insulation made from polystyrene, polyisocyanurate, or polyurethane. It is commonly used in construction to improve energy efficiency by reducing heat transfer. The boards are lightweight, easy to handle, and can be cut to fit various spaces, making them ideal for walls, roofs, and foundations. This insulation material provides a high R-value per inch, meaning it offers excellent thermal resistance. It is also moisture-resistant, which helps prevent mold growth and structural damage. Foam board insulation is often used in both residential and commercial buildings to enhance comfort and reduce energy costs.