Extruded polystyrene is a rigid foam insulation known for high moisture resistance and consistent thermal performance.

Extruded polystyrene, commonly referred to as XPS, is a rigid foam insulation material manufactured by extruding polystyrene resin into closed-cell boards. This process creates a dense, uniform structure with strong moisture resistance and stable insulating properties.

In construction, extruded polystyrene is widely used for below-grade insulation, foundation walls, slab edges, roofs, and exterior wall systems. Its closed-cell structure makes it well-suited for environments exposed to moisture, freeze-thaw cycles, and soil contact. XPS boards are lightweight, easy to cut, and available in various thicknesses and compressive strengths.

From a performance and code perspective, extruded polystyrene provides reliable thermal insulation and contributes to energy-efficient building envelopes. Proper installation, including joint sealing and protection from prolonged UV exposure, is important to maintain effectiveness. XPS is recognized by building codes and commonly specified where durability and moisture resistance are critical.

Extruded polystyrene is often identified by its distinctive blue, pink, or green color—each color usually tied to a specific manufacturer.

• XPS (Extruded Polystyrene Insulation)