Fixing and buying guide

What this product is and who it is for

This is a rigid polyisocyanurate (PIR) insulation board designed for trade and serious DIY customers undertaking thermal insulation work. It suits new build construction, refurbishment and retrofit applications where high-performance insulation and load-bearing capacity are required. The 1200 x 2400mm board format is sized for efficient handling and installation across multiple building elements without excessive cutting or waste.

Choosing the right product and brand

We stock five leading brands depending on current availability: Ecotherm, IKO, Mannok, Recticel and Unilin. You will receive whichever brand is in stock at the time of your order. All brands meet the same thermal and compressive strength specifications, so performance and compatibility are consistent across the range. Check your project specification or building control requirements if a particular brand is mandated.

• Thermal conductivity: 0.022 W/mK – high-performance insulation value
• Compressive strength: 175 kPa – suitable for load-bearing floor and structural applications
• 150mm thickness – standard depth for floor, wall and roof insulation
• 1200 x 2400mm board – efficient coverage and handling

Sizing and coverage

Each board measures 1200 x 2400 x 150mm and covers 2.88 square metres. Calculate your total insulation area and divide by 2.88 to determine the number of boards required. Allow extra boards for cutting, edge details, service penetrations and site waste. For floor applications, confirm joist or beam spacing and structural capacity before installation. For wall and roof work, verify cavity width, rafter spacing and any vapour control layer requirements with your building design.

Pre-installation checks and preparation

Before fixing, inspect the substrate for dampness, debris and structural soundness. Ensure the surface is clean, dry and level to minimise voids and thermal bridging. Confirm that your chosen fixing method – adhesive, mechanical fasteners or both – is compatible with the substrate and complies with building control and the board manufacturer's guidance. Check that vapour control layers, breather membranes and cavity trays are in place and correctly sequenced. Verify that the 150mm thickness integrates correctly with your wall build-up, floor construction or roof assembly, and that services and penetrations are planned to avoid unnecessary cutting.

• Substrate must be clean, dry and structurally sound
• Confirm fixing method and compatibility with substrate
• Check vapour control and membrane sequencing
• Verify thickness integration with overall build-up
• Plan service routes to minimise board cutting