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Celotex GA4100 General Purpose PIR Insulation Board - 2400 X 1200 X 100mm

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£45.28 Incl. VAT
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Product Description

Celotex GA4000 is a multi-purpose insulation board which can be specified for use in a variety of applications such as pitched roofs, flat roofs, solid masonry walls, floors, timber framed & steel framed systems. It has long been at the heart of the Celotex product range providing the user with a range of thermal insulation solutions.

With low emissivity foil facings, GA4000 is manufactured from rigid polyisocyanurate (PIR) using a blowing agent that has zero ozone depletion potential (zero ODP) and low global warming potential (GWP). Celotex 100mm GA4100 insulation board comes in the most popular thickness of 100mm, and provides long term energy saving opportunities for domestic, commercial and industrial buildings.


Length: 2.4m.
Width: 1.2m.
Coverage: 2.88m2.
Thickness: 100mm.
rValue: 4.50m2K/W.
Weight: 3.27kg/m2.
Thermal conductivity: 0.022 W/mk - BS EN 12667.
Compressive strength: ≥140kPa - BS EN 826.
Water vapour resistance: >150MNs/g - BS EN 12086: Method B.
Spread of flame: Class 1 - BS 476-7.


The insulation shall be Celotex GA4000 comprising a polyisocyanurate rigid foam insulation core, with a thermal conductivity of 0.022W/mK and low emissivity aluminium foil facings on both sides. GA4000 is A+ rated when compared to the BRE Green Guide 2008 and is CFC/HCFC free with zero ODP and low GWP.

Celotex GA4000 can be specifed for use in a variety of applications such as pitched roofs, flat roofs, solid masonry walls, floors, timber framed & steel framed systems.

CE marking compliance to BS EN 13165:2001 and manufactured in accordance with quality management systems BS EN ISO 9001:2000 by Celotex Limited. All products must be installed in accordance with instructions issued by Celotex Limited.

GA4000 Specifications

  • Comes in 100mm thickness, making it the thinnest PIR insulation available, in a standard board size of 1200mm x 2400mm.
  • Is suitable for use in a number of applications including roof, wall and floor systems.
  • Is easy to cut and shape.
  • Includes low emissivity foil facings giving improved thermal insulation performance within cavity air spaces.
  • Provides reliable long-term en


WIDTH 1200mm LENGTH 2400mm THICKNESS 100mm


Facing Foil Thermal Conductivity 0.022 W/mK Material PIR Edging Square Edge
Product Type Board

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Questions & Answers


Hello is this product suitable for underfloor insulation where full access is available - plenty of ventilation is also available. Would 100mm be an optimum thickness for this application ?


That would depend if you have been specified a thickness against the depth of the joists, as that would determine how thick the given insulation can be. 

Unfortunately we are not able to comment on what would pass/be the optimial thickness, this would be best suited for an Architect or perhaps even Building Control to advise on. 


Can Celotex be used as a cavity fire barrier?


No, where cavity fire barriers are required by national building regulations, they should be installed in line with the manufacturer's instructions.


Can Celotex be exposed to the ground?


We advise that when used in ground floors, Celotex must always be above the damp proof membrane (DPM ).


What is the U Value?


Unfortunately, we cannot calculate U Values. For this information, we recommend speaking to your builder or the manufacturer.

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Product Reviews

5 / 5 18 reviews
Gary S
2nd August 2021
Great product with excellent spec.
Sam Turner
23rd June 2021
Excellant service and price
Eamonn Finlay
18th May 2021
Garden room floor fully insulated.
17th May 2021
Good quality products
Adrian --
1st November 2020
Great product and easy to work with. When cutting I found the insulation itself was ‘smoother’ and less prone to ripping compared to other major brands I have recently purchased.
Andrew Pearson
22nd October 2020
Good quality product at significantly cheaper price compared to builders merchants.
Gabriel Vint
7th October 2020
does what it says on the tin.
4th October 2020
Excellent value
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Celotex GA4100 General Purpose PIR Insulation Board - 2400 X 1200 X 100mm

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