Celotex XR4000 Insulation Board

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Celotex XR4000 Insulation Board
Product Description

Celotex XR4000 is a multi-purpose insulation board developed to provide simple solutions for overcoming cold spots in walls, floors, and roofs from a lack of insulation. XR4000 is manufactured from rigid polyisocyanurate (PIR) with low emissivity foil facings. 

Size: 1200mm x 2400mm



size: 1200mm x 2400mm

We are happy to help with enquiries, stock availability or any technical help you require, however for security reasons we cannot take orders over the phone. So if you need to chat give us a call on 03301231761 or email us at [email protected].

What is Celotex XR4000? 

Celotex XR4000 is an environmentally-friendly polyisocyanurate (PIR) insulation board with excellent thermal performance, featuring a low emissivity foil facing. This board can be used for multiple applications for external walls and timber frames. It is available in thicknesses from 110mm to 200mm and can be considered for the roof, walls, and floor applications.


Lightweight and easy to install, Celotex XR4000 is a durable energy-saving solution which can help you save on heating bills. As well as eliminating cold spots and protecting your thermal environment, Celotex has been awarded an A+ rating in the BRE Green Guide.


The XR4000 insulation board has a thermal conductivity of 0.022W/mK.

Features and benefits of Celotex XR4000: 

  • 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.
  • Low emissivity foil facing provides improved thermal performance in sealed cavity air spaces, improving the achievable U-value.
  • Easy to install – Celotex boards are light and rigid assisting with ease of transportation, handling and fitting.
  • BBA certified – fit for use in defined roof, wall, and floor applications if installed, used and maintained as set out in the certificate.
  • Celotex XR4000 achieves a BRE Green Guide Rating of A, which can assist in demonstrating environmental performance in your BREEAM assessments.
  • Lightweight 2400 x 1200mm boards.
  • Low emissivity foil facing.

Applications for Celotex XR4000 insulation boards: 

  • Ground floor - concrete slab
  • Ground floor - suspended timber joist
  • Ground floor - beam and block
  • Upgrading existing concrete slab floor
  • External wall - timber frame sheathing
  • External wall - between timber frame studs
  • Pitched roof - over timber rafters
  • Pitched roof - sarking
  • Pitched roof - between timber rafters
  • Pitched roof - loft insulation - between and over timber joists
  • Flat roof - balconies and terraces over timber joists
  • Flat roof - between timber joists

Discover our Celotex buyer’s guide to find out more information about the brand’s insulation products.

Data Sheet (200.50 kB)
Safety Data Sheet (619.33 kB)
Customer Questions
What is the difference between Celotex TB4000, GA4000 and XR4000?
There is no difference, they are the same boards, just different thickness groups.
Can Celotex XR4000 boards be used directly below flooring tiles?
No, PIR insulation boards should not be used directly below flooring tiles. A suitable substrate such as screed should be used above the insulation boards, to distribute the load and prevent movement and cracking of the tiles. 
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More Information
SKUCelotex XR4000 Insulation Board
Supplier Part NumberXR4000
Size1200mm x 2400mm

Orders and Delivery

Free delivery if your order is over £300 ex VAT. Orders between £100 - £300 ex VAT will be subject to a delivery charge of £50 ex VAT. Please note, we are unable to accept orders less than £100 ex VAT

When ordering on line you can specify the date of delivery, however we would not be able to specify the time of delivery on that day.

• Please note that we have a number of large vehicles, including articulated vehicles that may be used for delivery. Please advise us in the comments on your order if access to the delivery address is limited.

• Due to insurance guidelines, delivery personnel are unable to enter private residences. Delivery will be as far as possible to the kerbside of the delivery address. The recipient of the products is responsible for any additional lifting once the delivery has been made. Please bear in mind that Insulation products can be bulky and / or heavy.

• The delivery driver will require a signature to confirm the goods have been received.

 † Unfortunately we, Insulation Express, cannot deliver to the Highlands & Islands of the UK. However we will be happy to deliver to a freight forwarding company on your behalf.


Returns and Refunds

In the unlikely event that you need to return an item, please contact our team on [email protected] within 14 days of accepting delivery of the item.

Restocking charges may apply. We will discuss this with you upon receipt of the cancellation request. Restocking charges will be applied where the products are no longer required AND NOT for goods returned because either defective or damaged.

We usually charge 30% of value (minimum £25.00).

Please note that we cannot accept returns on special orders. Special orders may consist of items sent via third party shipping companies or made to measure products. If you are unsure on whether or not your item is a special order, please contact us on [email protected] prior to placing the order.

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