Fastwarm 20mm Tile Backer Insulation Board

Fastwarm® 20mm Tile Backer Boards offer an excellent mid-thickness solution for projects where both thermal insulation and subfloor stability are critical. These boards are specifically engineered to work alongside our Fastwarm® 150w/200w/cable electric underfloor heating systems.

Despite their added thickness, they remain lightweight and are easily cut with a craft knife, making them perfect for installation in larger rooms or renovations where extra insulation is desired.

Boards can be laid over timber with mechanical fixings or bonded directly to solid substrates using flexible tile adhesive.

• Waterproof – Fully waterproof construction, approved by Ultra Tile adhesive manufacturers.
• Great Insulation Performance – Thermal conductivity of just 0.027 W/mK helps minimise back loss of heat.
• Excellent Sound Insulation – Improves acoustic comfort in any room.
• Ultra-Lightweight & Easy to Cut – Easily trimmed on-site with a utility knife.
• Strong & Durable – Supports compression loads up to 30 tonnes per m².
• Multi-Surface Application – Suitable for walls and floors (follow correct installation methods).
• Flexible Installation Options – Mechanically fix to timber or bond to solid subfloors with adhesive.
• Standard Size – Each board measures 1200 x 600 mm (0.72m²).

This board is 20mm thick — perfect when higher thermal resistance or build height is required. A 10m² area will generally need 14 boards.

Please note: Always use flexible tile adhesive and secure timber floors with mechanical fixings every 300mm.

Need a different thickness? Other options available: 6mm | 10mm | 12.5mm | 30mm | 50mm

Choose the board that best balances insulation performance with your floor build height.