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120mm Celotex XR4120 PIR Insulation Board 2400mm x 1200mm

URN: 3001019 In Stock
£49.99ex. VAT £17.36 per m2
£49.99ex. VAT
£17.36 per m2
Bulk Discount
15+ boards 30+ boards 40+ boards
£49.49ex. VAT £48.99ex. VAT £48.49ex. VAT
Celotex XR4120 is a high-performance thermal insulation PIR board with composite foil facings. It can be used for roof, floor, wall and timber joist applications.

Express Delivery

Tue 28 Mar

Standard Delivery

Wed 29 Mar

Product Overview

Celotex XR4120 is a high-performance thermal insulation PIR board with composite foil facings. It can be used for roof, floor, wall and timber joist applications.

120mm Celotex XR4120 PIR Insulation Board 2400mm x 1200mm

URN: 3001019
£49.99ex. VAT

Delivery & Returns Information

All delivery charges are shown in your basket and are dependent on the total value of items in your basket based on product category.

Standard (Nationwide) Delivery

Insulation, Plasterboard and Drylining
Under £150 ex. VAT £75 ex. VAT
Between £150 - £300 ex. VAT £50 ex. VAT
Between £300 - £500 ex. VAT £25 ex. VAT
Over £500 ex. VAT FREE
Building Material Products
Under £300 ex. VAT £50 ex. VAT
Between £300 – £500 ex. VAT £25 ex. VAT
Over £500 ex. VAT FREE
Under £100 ex. VAT £7.50 ex. VAT
Over £100 ex. VAT FREE
SuperFOIL and YBS products
Each item £10 ex. VAT
Over £350 ex. VAT of 1 brand FREE

Express Delivery

Under £300 ex. VAT £75 ex. VAT
Over £300 ex. VAT £50 ex. VAT

This charge is based on delivery to mainland UK excluding the Scottish Highlands. If your delivery address is in the Scottish Highlands a member of our customer service team will contact you prior to processing your order should an additional delivery charge apply. We do not offer deliveries outside the UK mainland.

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We offer a 30 day returns policy on any faulty products.

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Key Features

  • Use in floors, framed walls and pitched roofs
  • Aluminium composite facing on both sides
  • 0.022 W/mK thermal conductivity
  • Easy to handle and install
  • Zero Ozone Depletion Potential (ODP)
  • BBA certified

Technical Specification

Technical Specification
Material Type:PIR
Sales Unit:Board
Sales Unit Coverage:2.88m2
Manufacturer's Reference:XR4120
Thermal Conductivity:0.022W/mK

Product Description

Minimise heat loss by creating a thermal barrier with Celotex Insulation XR4120; 'XR' meaning 'Extra Resistance', with the XR4000 range featuring sizes thicker than 100mm. Featuring foil facings, the 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). 

With a low thermal conductivity of just 0.022 W/m.K, Celotex XR4120 delivers the required U-values with minimal thickness and helps meet the current and future requirements of the Building Regulations. Celotex XR4120 is suitable for use in a number of applications including roof, wall and floor systems. 

120mm Celotex XR4120 PIR Insulation Board Applications

Celotex XR4120 is a highly versatile multi-purpose insulation board ideal for various applications including pitched roofs, solid floors, masonry walls, timber frames and steel frames. The XR4120 is produced to the highest manufacturing standards and has a BBA (British Board of Agrement) certificate as fit for use in defined roof, wall and floor applications.

Celotex XR4120 insulation board is an effective thermal insulation solution suitable for use in the following applications:

  • Solid concrete floors
  • Block, and beam floors
  • Suspended timber joist floors
  • Pitched roofs
  • Partition wall and solid masonry wall constructions
  • Timber framed & steel framed systems

Celotex XR4120 PIR Insulation Board Specifications

This convenient high-performance insulation board has excellent thermal performance and an impressive thermal conductivity of 0.022 W/mK. 120mm Celotex boards are the go-to thermal insulation solution for environmentally conscious individuals who want to improve heat retention in their homes and make long term energy savings. They are manufactured with eco-friendly concepts in mind, manufactured using a blowing agent with low global warming impact and zero ODP (zero ozone depletion potential). 

Let's take a look at the specs: 

  • Thermal conductivity of 0.022 W/mK - low U-values can be achieved without doubling-up insulation layers
  • Moisture-resistant
  • Low Global Warming Potential (GWP) and Zero Ozone Depleting Potential (ODP)
  • Features low emissivity foil facings giving improved thermal insulation performance within cavity air spaces
  • Easy to cut and shape
  • Provides reliable long-term energy savings for buildings

Celotex XR4120 PIR Insulation Board Certifications

BS EN is British and European Standard Specifications. With over 100 years of experience, the British Standards Institute is recognised as the UK’s National standards body. BS EN considers Celotex XR4120:

  • Spread of flame: Euroclass E Reaction to Fire classification, according to BS EN 13501-1
  • Thermal conductivity of 0.022 W/m.K, reducing the thickness of insulation required to hit the target U-value - BS EN 12667
  • BRE Green Guide Rating of A for sustainability - which can assist in demonstrating environmental performance in your BREEAM assessments
  • BBA certified

120mm Celotex Insulation Storage & Handling

These Celotex XR4000 range boards are lightweight and easy to handle. If you need to store 120mm Celotex boards for a while before installation, you should choose a cool, dry space. 2.4m x 1.2m insulation boards are not for external use, and therefore they should not be left outside for extended periods of time or allowed to get wet.

About Celotex 

Celotex is a leading British manufacturer of 120mm PIR insulation. It was founded decades ago and has since evolved from a fibreboard insulation company to one that focuses on PIR boards. The XR4120 insulation board is just one of many popular thermal insulation solutions from Celotex XR4000 product range, with thicknesses ranging from 110mm to 150mm.

They are manufactured in accordance of quality management systems and are water vapour resistant. Celotex XR4120 helps to achieve lower U-Values, energy use and carbon dioxide emissions targets set by the national building regulations.


5/5 based on 12 reviews

easy to work with and cut

Russ Beck on

Great customer experience from start to finish

Jill K on

Really lightweight considering how big each board looks

Martin Budge on

Exactly what I needed for my loft conversion

Dave Burley on

I always buy Celotex, the service of Materials Market was great

Jack Ryan on

Came on time and cheapest I found online

Craig Jawson on

Really easy to install

William Culvers on

Great insulation at a good price

Martin Chivers on

Excellent thermal performance. Foil facings on both sides meant I did need to buy some additional tape which was also inexpensive.

Will Barker on

Great service from start to finish

Janet W on

excellent boards

Steve Carell on


Brian Kremer on

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