Celotex PL4000

Celotex PL4000 is an easy to install polyisocyanurate (PIR) insulation board with a paper facing, laminated to a piece of 12.5mm tapered edge plasterboard. Available in thicknesses from 25mm to 65mm (insulation only),  it can be considered for use in roof and internal wall lining applications.

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Product Features


  • Standard 1200 x 2400mm boards
  • Paper facing
  • BBA approved – certificate 16/5357 (Plasterboard Thermal Laminate)


Fire Classification

Euroclass B-s1, d0 Reaction to Fire classification, according to BS EN 13501-1.

Product Specification

Thickness (mm)* Length (mm) Width (mm) Lambda Value (W/m.K) R-Value (m².K/W)#
37.5 2400 1200 0.022 1.20
52.5 2400 1200 0.022 1.85
62.5 2400 1200 0.022 2.30
72.5 2400 1200 0.022 2.75
77.5 2400 1200 0.022 3.00

* Thickness includes 12.5mm plasterboard
# R-Value including plasterboard.

Product Benefits


  • Thermal Performance - Excellent thermal performance with a thermal conductivity of 0.022 W/m.K, reducing the thickness of insulation required to hit the target U-value.
  • Time Saving - Celotex PL4000 brings together both insulation and plasterboard creating a 2-in-1 solution to insulate and dry line walls or roofs at the same time.
  • Easy to Install - Celotex boards are rigid assisting with ease of transportation, handling and fitting.
  • BBA Certified - Celotex PL4000 has been assessed by the BBA as fit for use in plasterboard thermal laminate applications if installed, used and maintained as set out in the certificate. Please read the BBA certification page for full details and restrictions.


Key Considerations

When using Celotex PL4000, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions.
Please refer to the following product documents:

Celotex PL4000 should not be used in the external walls of buildings over 11 metres in height. Recent changes to Building Regulations mean that only non-combustible insulation or insulation of limited combustibility should be used in buildings of that height.