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Celotex PL4000

High performance plasterboard thermal laminate insulation for dry-lining applications.

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What is Celotex PL4000?

A plasterboard laminate product featuring 12.5mm tapered edge plasterboard bonded to a high thermal performance, rigid polyisocyanurate (PIR) insulation board. PL4000 reduces installation time by combining thermal insulation and an internal lining in one operation.

Suitable for use in new build and refurbishment projects, PL4000 can be fixed across the face of timber frame studs, or joists and rafters in pitched and cold (ventilated) flat roofs. It can also be fixed to the internal face of existing solid walls or cavity walls to upgrade their thermal performance.

As well as being CE-marked, Celotex PL4000 is certified by the British Board of Agrément for use as insulating dry lining for internal wall applications. Made at our original site in Hadleigh or our state-of-the-art facility in Eggborough (opened in 2018), you can be confident of it providing reliable, long-term energy savings.

How does PL4000 perform?

The insulation used in the entire thickness range offers a low thermal conductivity (lambda value) of 0.022 W/mK, putting PL4000 among the best-performing widely-available thermal laminates on the market.

In any of its intended applications, PL4000 will help to provide most of the thermal insulation performance - but the overall heat loss from a building element depends on all of the materials used and the way they’re installed. Use our online and mobile U-value calculators to help you find the most efficient solution for each type of construction.

Product benefits

Celotex PL4000 can be mechanically fixed or adhered to masonry walls using ‘dot and dab’ plaster. With an insulation thickness as low as 15mm, it can also be used to line door and window reveals and help maintain continuity of the building’s thermal envelope.

The composite facing to which the plasterboard is bonded features an aluminium layer sufficient to act as a vapour control layer - including the internal upgrade of existing solid walls, subject to appropriate moisture assessment in accordance with BS 5250 (control of condensation in buildings).

Check our frequently asked questions for common queries about positioning and installing products correctly, or contact our technical services team.

Like all Celotex products, PL4000 is a thermal insulation solution that can help to meet energy use and carbon dioxide emissions targets set by national building regulations.

  • Board size: 1200 x 2400mm
  • Thickness : 15-65mm
  • Lambda: 0.022 W/mK
  • Facer: 12.5mm tapered edge plasterboard; multi-layer composite
  • Insulation manufactured using a blowing agent with zero ozone depletion potential (ODP) and low global warming potential (GWP).


1With regard to plasterboard thermal laminate, the BBA certification assessed thermal performance, condensation risk, water resistance and durability.


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