Celotex PIR Insulation Board 1200 × 2400

The Celotex PIR insulation board is a high-performance, rigid solution suitable for floors, walls, roofs, ceilings, and dormer cheeks. With foil facings on both sides and a fibre-free PIR core, Celotex provides excellent thermal insulation and is ideal for both new construction and upgrading existing structures.

Why Choose Celotex PIR Boards?

Celotex boards are engineered for multi-application use, offering efficient insulation for flat and pitched roofs, solid masonry walls, timber frames, and floors. Their low thermal conductivity allows for thinner build-ups while achieving U-values that meet current Building Regulations.

Core & Facing / Technical Highlights

• Thermal conductivity (λ): 0.022 W/m·K (typical)
• Thickness range: 25 mm up to 150 mm (varies by board type)
• Compressive strength: ~140 kPa at 10% compression (per BS EN 826)
• Foil composite facings both sides for improved radiant heat control
• BBA Certification: Celotex is BBA certified for relevant applications
• Integral vapour control: The foil facings act as a vapour control layer in many installations

Application & Suitability

• Cold flat roof insulation
• Pitched roofs / ceiling voids
• Solid masonry walls (internal or external)
• Timber frame and stud walls
• Floor insulation (above or below slab layers)
• Dormer cheeks, room-in-roof scenarios, and loft conversions

Performance in Practical Use

Celotex PIR boards allow you to achieve low U-values with reduced thickness compared to mineral wool or EPS. Their rigidity supports installation under floors and roof loads. The foil facings provide an integral vapour control effect, though additional VCL may be needed in high-humidity areas fol