Insulation underlay extruded polystyrene - thk. 5 mm, 700 kPa - pack 13.5 m² HD-XPS700/18

Premium insulation underlay HD-XPS700

The HD-XPS700 insulation underlay is a premium extruded polystyrene board with a thickness of 5 mm and exceptional compressive strength of ≤700 kPa. It is specifically designed to work with Heat Decor underfloor heating systems and serves as a universal underlay for various types of floating floors.

Construction and material properties

The HD-XPS700 extruded polystyrene (styrodur) features a closed-cell structure, which provides excellent insulating properties. The thermal conductivity coefficient is 0.033 W/(mK), guaranteeing effective protection against heat loss. The material maintains stability across a wide range of operating temperatures from -50°C to +75°C.

The compressive strength of ≤700 kPa (equivalent to approximately 70 tons/m²) allows for safe use even under heavy loads. The board meets the T1 thickness tolerance class requirements, ensuring a uniform installation surface.

Application and compatibility

The product is widely used as an underlay for:

• SPC vinyl panels - meets the CS = 700 kPa requirement for this type of flooring
• Laminate panels - provides a stable installation surface
• Engineered wood - levels out minor substrate irregularities

In the Heat Decor heating system with HD-G, HD-EPL, or HD-PRO heating films, the board serves a multifunctional role—there is no need to purchase a separate acoustic or thermal underlay. The 5 mm thickness allows for efficient routing of the heating system cables.

User benefits and ecology

Thanks to its closed-cell structure, the material is moisture-resistant, does not absorb water via capillary action, and effectively prevents surface dampness. It is also resistant to biological factors—it does not rot or grow mold.

The board effectively directs heat from the heating system toward the room, allowing for rapid temperature increases while simultaneously eliminating heat loss. It prevents floor deflection that causes unwanted noises.

Less energy consumed for heating means a more eco-friendly building.