The most popular product range manufactured by Celotex, GA4000 is a high performance, rigid polyisocyanurate (PIR) insulation board with low emissivity foil facings bonded to each side, specifically designed for multi-purpose applications. This product uses a combination of blowing agents with low global warming potential and zero ozone depletion potential (zero ODP).
GA4000 is available in size 2.4m by 1.2m with thicknesses from 50mm to 100mm and thermal conductivity of just 0.022W/mK. This product is lightweight and easy to cut, handle, and install
It can be used throughout a building project to help maintain continuity of the insulation envelope and is suited to floor, wall, and roof systems.

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Celotex GA4000

  • Multiple Application Methods
  • Tapered edge
  • Can be used to improve the standards of the current building regulations.
  • Keeps energy bills low long term and maximises savings.
  • Creates a more energy efficient environment.
  • Can be applied to extensions, refurbishments, and new build projects.
  • Inbuilt vapour control layer
  • Energy efficient
  • Helps to meet the requirements of UK thermal building regulations
  • Thermal conductivity of PIR products does not change over time
  • Easy installation

Supplying your home with the correct insulation materials will provide a more energy efficient and sustainable environment by helping towards the prevention of global warming and climate change. This will also save you money on your energy bills by keeping heat from within your property.

The Celotex packaging should not be considered as protection for the board against weather condition. The insulation board should be stored on a flat surface in weatherproof conditions preferable inside a building. If the boards should have to be stored outside the correct weatherproofing materials should be provided as protection. Boards that have been allowed to get wet should NOT be used.

Celotex PIR Insulation Board GA4000 can be installed in a range of methods. These methods include:

  • Ground floors – whether solid concrete, block and beam, or suspended timber joist, and including where underfloor heating is used.
  • Timber and steel-framed walls – between and across the face of studs.
  • Pitched roofs – between and across the face of rafters.
  • Flat roofs – in ventilated cold roof constructions, installed from inside the building.
  • Other retrofit and refurbishment projects – lining existing timber and masonry structures to make them more thermally efficient.

To find out more about Celotex PIR Insulation Board sizes, see our guide below:

Reaction to Fire classification, according to BS 476-7:1997
Achieves a BRE Green Guide rating of A+.
All Celotex products are manufactured under Quality Management Standard – ISO 9001:2015
Certified under BBA certificate number 17/5405 and 16/5352
Quality management system ISO 9001
Environmental management system ISO 14001.

More Information:
Available in sizes: 50mm, 60mm, 70mm, 75mm, 80mm, 90mm, 100mm
Product Code: GA4000
Thermal Conductivity: 0.022 W/mK
Material: Polyisocyanurate (PIR)
Dimensions; 2.4m x 1.2m

GA4000 Datasheet:

Stocked Thickness50mm60mm70mm75mm80mm90mm100mm
Lambda Value (W/mK)0.0220.0220.0220.0220.0220.0220.022
R-Value (m2.k/W)2.252.703.153.403.604.054.50
Length (mm)2400240024002400240024002400
Width (mm)1200120012001200120012001200
Maximum Weight (kg/m2)1.922.262.612.782.963.314.15
Pieces per Pallet48403230302424

How to fit Celotex GA4000 insulation into solid walls

Before installing:

  • This board can be cut using a fine-toothed saw, this is accomplished by measuring the boards to size and making markings if necessary. Then placing the boards on a surface that allows the saw to go all the way through the board. A knife can also be used to score the board, then snap the board over a straight edge, and cut the facing on the other side. Any of the insulation board cut offs should be kept in case of gaps within the installed insulation.
  • Protective clothing is recommended to prevent particles produced from cutting the insulation boards from causing irritation to the eyes or skin. Goggles, face masks, and gloves should be worn to provide protection.Bottom of Form
  • For heavy wall mounted parts, use independent horizontal battens. You may also need longer fixings to fit heavy items to the masonry, separate of the battens.
  • Celotex insulation boards: Celotex TB4000, Celotex GA4000, PL4000.
  • Timber battens, Insulation tape, sealant and the required fixtures and fittings.

Step one: Ensure the wall is clean, dry, dust free and any wallpaper or gloss paint has been removed. The wall should be in good condition and any remedial work done prior to installation of the boards to remove dampness is complete.

Step two: Cut the relevant insulation boards to size to meet the measurement of the room floor-ceiling. The unprinted foil surface should be placed facing the batten cavity for top thermal performance.

Step three: Fix horizontal battens over the insulation board at the top and bottom of the wall to keep the insulation boards in place. Ensure each board joint is sealed.

Step four: Create a vapour control layer using insulation tape

Step five: Place further vertical battens over the insulation at the appropriate spacing -this will provide suitable fixings for the desired lining system. Make sure a batten meets with each lining board joint.

Note: For window and door reveals, Celotex TB4000 boards are recommended to reduces the risk of thermal bridging. Install the batten around the edge of the opening and scribe the board to fit the reveal. Cut the dry lining to suit and mechanically fix into the masonry using the required fixings.

Step six: Use an angle fillet at the frame and an angle bead at external corners to finish. Scrim tape can also be applied to any adjoining boards to prevent cracking. Also apply appropriate sealant around the perimeter of the insulation – this will provide a vapour seal.

Step nine: Use further battens -minimum 50mm x 25mm treated softwood- around all openings to provide fixings for linings, grounds for skirting etc. If cables are located within the cavity created by the batten, increase the batten depth to ensure tubing is considered.