Fixing and buying guide

What this product is and who it is for

Rigid PIR (polyisocyanurate) insulation board is a closed-cell foam material engineered for thermal performance and structural stability. It is suitable for builders, contractors and experienced DIY installers working on new build projects, refurbishment schemes and retrofit thermal upgrades. The 120mm thickness addresses mid-range insulation requirements in building fabric upgrades where cost-effectiveness and handling ease are priorities.

Compatibility and applications

This board is specified for use in floors, walls and roof applications. The 175 kPa compressive strength is appropriate for typical loading conditions in these locations. Ensure your building design and local building regulations confirm suitability for your specific application, loading scenario and thermal requirement. BBA certification supports building control sign-off.

• Floors: suitable for timber joists and concrete substrates under normal domestic and light commercial loading
• Walls: compatible with timber frame, masonry and cavity wall applications
• Roofs: appropriate for pitched and flat roof constructions within design load limits
• Confirm compressive strength adequacy for your specific structural loading before installation

Sizing, pack contents and board format

Each board measures 1200 x 2400 x 120mm. This standard format is designed for straightforward handling and installation. Calculate your total insulation area requirement and divide by the board area (2.88 m²) to determine quantity needed. Account for cutting waste and edge details in your calculation. Boards are supplied by Ecotherm, IKO, Mannok, Recticel or Unilin depending on availability; all meet the same performance specification.

• Board area per unit: 2.88 m²
• Thickness: 120mm suits mid-range thermal upgrades
• Standard 1200 x 2400mm format minimises handling difficulty
• Supplier brand varies by stock availability but thermal and structural performance is consistent

Pre-installation checks and preparation

Before fixing, inspect boards for damage and confirm the substrate is clean, dry, level and structurally sound. Verify that your building design confirms the 175 kPa compressive strength is adequate for the intended application and loading. Check local building regulations and ensure BBA certification is noted for building control purposes. Plan your layout to minimise cutting waste and ensure boards are staggered at joints. Allow boards to acclimatise to site conditions for 24 hours before installation.

• Inspect all boards for transit damage before installation
• Confirm substrate is clean, dry and level
• Verify structural adequacy of 175 kPa compressive strength for your application
• Plan board layout to stagger joints and minimise waste
• Allow 24-hour acclimatisation to site temperature and humidity