Our foil-coated, high-density XPS400 overlay boards are lightweight, durable, and simple to install. Designed for both new and existing floors, they provide a fast and efficient way to fit water underfloor heating with minimal disruption. The aluminium foil surface enhances heat transfer, ensuring optimum system performance for both residential and commercial applications.

Versatile & Easy to Install

Suitable for use beneath laminate, engineered wood, carpet, vinyl, and tile flooring, the XPS400 overlay panels are ideal for retrofit installations. They can be laid directly onto concrete, timber, or solid floors, adding just 20mm to the overall floor height. With a compressive strength of 400 kPa, the panels are strong, lightweight, and can be fitted using only basic tools.

Panel Specifications

• Panel size: 1200 × 600 × 20mm
• Coverage: 0.72m² per panel
• Pipe size: 15mm or 16mm
• Pipe centres: 150mm
• Material: High-compressive-strength Extruded Polystyrene (XPS)
• Aluminium layer: For fast, even heat distribution
• Compressive strength: 400 kPa
• Recommended adhesive: Rapid Response Spray Adhesive

The aluminium coating ensures heat spreads quickly and evenly across the surface, maximising output and system efficiency. Panels should be installed on a clean, level surface and securely fixed using Rapid Response Spray Adhesive.

Made from high-compressive-strength extruded polystyrene (XPS), these 400 kPa panels combine excellent insulation properties with outstanding structural integrity.

Please note: Due to product fragility, XPS400 boards can only be shipped by pallet.

Adhesive Consumption Rate

• Wood or tiled subfloor: Approx. 5m² per can – spray only the subfloor, then lay the board onto the adhesive.
• Concrete or porous subfloor: Approx. 2.5m² per can – spray both the subfloor and the underside of the board to achieve a “glue-to-glue” bond.

Flooring Compatibility & Installation

Laminate / Engineered Wood

• Lay directly as a floating floor
• Use a breathable underlay if planks are not pre-bonded
• Maximum plank thickness: 20mm

Carpet / Vinyl / LVT 

• Prime with Mapei Eco Prim Grip, or similar
• Apply 5–10mm fibre-reinforced self-levelling screed (e.g. Mapei Ultraplan or similar)
• Ensure all grooves and channels are completely filled
• Combined carpet + underlay should not exceed 2 tog

Tile / Stone

• Prime with Mapei Eco Prim Grip
• Apply 5–6mm self-levelling screed
• Fix tiles using Ultra ProFlex S2 Flexible Tile Adhesive, or similar
• Maximum tile thickness: 20mm (ideal ≤15mm)

Why Choose?

• Easy retrofit solution with minimal disruption
• Superior heat distribution and efficiency
• Lightweight yet strong and durable
• Compatible with almost any finished floor type
• Designed for professional or DIY installation