XPS (Extruded Polystyrene)

Definition: XPS (Extruded Polystyrene) is a type of rigid foam insulation commonly used in roofing applications, particularly for flat and low-slope roofs. It is made through an extrusion process that produces closed-cell foam, giving it excellent thermal resistance, moisture resistance, and durability. It is often installed beneath roofing membranes or over roof decks to improve a building’s energy efficiency and protect the structure from temperature fluctuations.

Extruded Polystyrene in Roofing:

• Flat and Low-Slope Roofs: XPS is commonly used in flat or low-slope roofs as part of the insulation layer beneath waterproof membranes. It helps regulate the building’s temperature and provides a stable, water-resistant foundation for the roof covering.
• Inverted Roofing Systems: In inverted (or “protected membrane”) roofing systems, XPS insulation is installed above the waterproofing membrane. This design protects the membrane from temperature extremes and mechanical damage, while the insulation remains unaffected by moisture.
• Tapered Insulation Systems: Material is often used in tapered insulation systems, where the insulation boards are cut at an angle to create a slope on flat roofs. This helps direct water to drainage points, preventing water pooling and extending the roof’s life.

Read more: The Role of Snow Guards on Metal Roofing in Canada

XPS Environmental Impact:

• Recyclability: XPS can be recycled and reused in some applications, helping reduce its environmental footprint.
• Blowing Agents: Traditional extruded polystyrene manufacturing processes used blowing agents with high global warming potential (GWP), but many manufacturers have shifted to more eco-friendly options to reduce the environmental impact.