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Celotex XR4000 Insulation Boards

(7 Products)

Celotex Insulation XR4000 is the code Celotex gives their multi-purpose 'Extra Resistance' insulation boards; in sizes thicker than 100mm. The 2.4m x 1.2m boards have zero ozone depletion potential (zero ODP) and low global warming potential (GWP) and boast a PIR foam core sandwiched between two low emissivity foil facings. With a thermal conductivity of just 0.022 W/m.K, the boards are suitable for use in a number of applications including roof, wall and floor systems.

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What Is Celotex XR4000? 

The Celotex XR4000 distinguishes itself by being the thickest insulation offering within the Celotex product range. 

Its substantial thickness not only underscores its robustness but also its enhanced capacity to retain heat, making it an optimal choice for those seeking maximum thermal insulation efficiency in their projects.

Celotex XR4000 is a multi purpose insulation board employed in scenarios where a more substantial thickness is necessary to achieve the desired thermal insulation levels, or "U-values."

The availability of Celotex XR4000 ranges in thickness from 110mm to 200mm, providing options to suit various insulation requirements.

Celotex XR4000 Insulation Board Applications

Celotex XR4000 insulation board offers excellent thermal properties thanks to its low-emissivity foil facing on either side, giving improved thermal performance within sealed cavity air spaces. Celotex XR4000 is targeted at ‘cut-to-fit’ applications between rafters or joists and enables users to achieve lower U-values with a single layer of insulation. 

XR4000 multi-purpose insulation board boasts excellent thermal performance and has been certified by the BBA for use in defined roof, wall and floor applications.

Celotex XR4000 insulation board can be specified for use in the following applications:

  • Pitched roofs
  • Solid masonry walls
  • Timber framed & steel framed systems
  • Floors


Celotex XR4000 PIR Insulation Board Key Features

Celotex XR4000 2.4m x 1.2m boards are manufactured from rigid polyisocyanurate (PIR) using a blend of blowing agents that have zero ozone depletion potential (zero ODP) and low global warming potential (GWP). Let's have a look at the specs:  

  • Thermal conductivity of 0.022 W/mK - high performance
  • Moisture-resistant
  • Improves the achievable U-value of a project 
  • Low Global Warming Potential (GWP) and Zero Ozone Depleting Potential (ODP)
  • Achieves a BRE Green Guide Rating of A - which can assist in demonstrating environmental performance in your BREEAM assessments
  • Helps meet the current and future requirements of Building Regulations
  • Features low emissivity foil facings giving improved thermal insulation performance within cavity air spaces
  • Easy to cut and shape
  • Light and rigid assisting in transporting 
  • Easy to install polyisocyanurate (PIR) insulation board
  • Provides reliable long-term energy savings for buildings


Celotex Fire Classification

Celotex XR4000 PIR Insulation Board is tested to BS EN 13501-1 with a classification of E. Simply put, this means it is combustible and will contribute to the overall fire load. Because of this, the boards must not be used in the external facades of buildings over 18m in height in England and Wales or over 11m in height in Scotland.

When using Celotex XR4000, please ensure your installation meets all relevant national Building Regulations and guidance and local, national and other applicable standards relevant to your construction or application.

Celotex Thicknesses

The most popular Celotex PIR general application insulation board in our range is 2400mm long and 1200mm wide. You might see products labelled Celotex XR4110, Celotex XR4150, and Celotex XR4130, however, all these products have the same dimensions in terms of length and width. The only difference between these boards is that they each have different thicknesses.

Simply put, the different codes represent these different thicknesses. We stock a sliding scale of boards that suit every situation from thinner solutions starting at 20mm thick, all the way up to 150mm thick boards. And if that's not enough, you can always consider using two-layer build-ups.

Celotex boards reduce the thickness of insulation required to hit the target U-Value. Follow our handy Celotex thickness guide to find a PIR insulation board that suits your project.

Celotex XR4000 - 110mm, 120mm, 130mm, 140mm, and 150mm thickness

For further details, please refer to the data sheets on our site. Each product in our range comes with a data sheet written by the manufacturer so you get all the information from the horse's mouth. Simply click on the 'Technical Downloads' tab, next to the 'Product Overview' tab.

Other Available Celotex Product Ranges

Frequently Asked Celotex XR4000 Questions

What Is The Difference Between Celotex XR4000 and GA4000?

The Celotex XR4000 distinguishes itself by being the thickest insulation offering within the Celotex product range. This suits it to applications where maximum thermal insulation efficiency is required. 

GA4000, on the other hand, is suited for more general applications, such as in the wall, floor and roof. 

What Is The Difference Between Celotex GA4000 and GA4100?

GA4000 boards are renowned for their versatility, making them a highly favoured choice among users. The 100mm version of GA4000, identifiable by the product code GA4100, stands out as the top-selling product in the Celotex lineup. 


What Is The Difference Between Celotex and Kingspan?

The main variations between PIR and phenolic are found in the substances from which they are crafted and their respective manufacturing methods. 

Although PIR offers impressive insulation capabilities, phenolic surpasses it in overall thermal efficacy. With a thermal conductivity rating reaching a mere 0.018 W/mK, in contrast to the 0.022 W/mK associated with PIR, phenolic emerges as the predominant insulation option. 

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