What material is typically used to construct rigid insulation boards?

Rigid insulation boards are predominantly made from plastic foam materials, such as expanded polystyrene (EPS), extruded polystyrene (XPS), or polyisocyanurate. These materials are specifically chosen for their excellent thermal resistance properties and lightweight nature, making them ideal for insulating roofs and walls. The cellular structure of plastic foam allows for low thermal conductivity, which helps to reduce energy costs by maintaining the desired temperature within a building. Additionally, plastic foam materials are resistant to moisture, making them suitable for use in varied weather conditions without deteriorating over time. This combination of energy efficiency and durability highlights why plastic foam is the prevalent choice for constructing rigid insulation boards.