Fixing and buying guide
QL Kraft PIR Insulation 2400mm x 1200mm x 40mm + 12.5mm Insulated Plasterboard
What this product is and who it is for
This is a factory-bonded insulation board combining PIR foam core with plasterboard facing, designed for builders and serious DIYers undertaking roof and wall insulation projects. The kraft paper facing on the PIR side provides a vapour control layer, whilst the plasterboard face offers a ready-to-decorate finish. It is ideal for homeowners and contractors looking to improve thermal performance and reduce installation time by combining insulation and boarding in one product.
Sizing and coverage
Each board measures 2400mm length by 1200mm width, providing 2.88 square metres of coverage per sheet. The total thickness is 52.5mm (40mm PIR plus 12.5mm plasterboard). Calculate your project area and divide by 2.88 to determine the number of boards required. Account for waste and cutting around obstacles when ordering.
- Board dimensions: 2400mm x 1200mm
- Coverage per board: 2.88 square metres
- Total thickness: 52.5mm
- PIR core: 40mm, Plasterboard: 12.5mm
Installation methods
The board can be fixed using two approaches depending on your application. For rafter applications, mechanical fixings secure the board directly to the timber structure. For dry-lining on internal walls, use dot-and-dab adhesive application or mechanical fixings to attach the board to the existing wall surface. The kraft paper facing should face the insulation side, with the plasterboard face exposed for finishing.
- Rafter installation: mechanical fixings to timber structure
- Dry-lining: dot-and-dab adhesive or mechanical fixings
- Kraft paper facing acts as vapour control layer
- Plasterboard face ready for decoration after installation
Pre-installation checks and preparation
Before fixing, ensure the supporting structure (rafters or wall) is sound, dry, and free from debris. Check that the surface is level and suitable for your chosen fixing method. Store boards flat and protect from moisture during transit and on site. Measure your space carefully and plan board layout to minimise cutting and waste. Ensure adequate ventilation in roof spaces and follow building regulations for thermal performance and fire safety in your application.
- Inspect supporting structure for soundness and dryness
- Store boards flat and protect from weather
- Plan layout to minimise waste and cutting
- Verify compliance with building regulations for your application