100mm Celotex GA4100 PIR Insulation Board 2400mm x 1200mm

URN: 3001017 In Stock
£36.30ex. VAT £12.60 per m2
£36.30ex. VAT £12.60 per m2
15+ boards 30+ boards 50+ boards
£36.12ex. VAT £35.94ex. VAT £35.76ex. VAT

100mm Celotex GA4100 PIR Insulation Board 2400mm x 1200mm

URN: 3001017
£36.30ex. VAT

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Between £150 - £300 £50
Between £300 - £500 £25
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Note: Values/Charges ex VAT

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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:GA4100
Thermal Conductivity:0.022W/mK

Product Description

Houses will always lose heat; heat loss will not only harm your comfort levels but will also make a dent in your pocket and the planet. This is where Celotex GA4100 100mm comes in. 100mm Celotex is the most popular Celotex insulation thickness on the thermal insulation market. It is a high performance, versatile insulation solution, which can be used for roof, floor, wall and timber joist applications.

The 2.4m x 1.2m boards are manufactured with a specially designed blowing agent that has a low potential to cause global warming. This is demonstrated in the fact that the boards have zero ozone depletion potential (ODP) and low global warming potential (GWP). 

What's more, 100mm Celotex PIR boards showcase low-emissivity foil facings on either side which increase their thermal performance in sealed air cavities; producing a superior U Value to other insulation solutions on the market with a thermal conductivity of just 0.022 W/m.K.

100mm Celotex GA4100 PIR Insulation Board Applications

As a general application insulation board (implied by the 'GA'), this BBA certified PIR insulation board can be used in a wide variety of building applications; including solid masonry internal linings, timber joist floors (including suspended timber joist floors), and timber frame studs. 

Not only that, but it can also be used in solid floor systems such as screed and concrete slab floors. Quite the all-rounder.

Celotex GA4100 can be specified for use in a variety of applications including:

  • Pitched roofs
  • Solid masonry walls
  • Timber frames & steel framed systems
  • Timber frame internal linings
  • Floors - screed, concrete slab and timber joist floors
  • Loft insulation – between and over timber joists (pitched roof)
  • Timber frame sheathing (external wall)
  • Between timber frame studs (external wall)
  • Solid masonry internal linings (external wall)

Celotex GA4100 Specifications

100mm Celotex GA4100 insulation is a multi-purpose insulation board that comes in dimensions of 2.4m x 1.2m. Not only do the boards offer excellent thermal performance, but they are also moisture resistant thanks to their closed-cell structure. 

This excellent drying potential sets you up for years of consistent thermal performance - promising maximum protection for the lifetime of your build.

Let's have a look at the specs:

  • Suitable for use in a number of applications including roof, wall and floor systems
  • Thermal conductivity of 0.022 W/mK
  • Moisture-resistant
  • Low Global Warming Potential (GWP) and Zero Ozone Depleting Potential (ODP)
  • Achieves an A+ rating when compared to the BRE Green Guide 2008
  • 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 GA4100 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.

  • 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
  • Compressive strength: ≥140kPa - BS EN 826
    BRE Green Guide Rating of A for sustainability - which can assist in demonstrating environmental performance in your BREEAM assessments
    BBA certified

Celotex GA4100 Insulation Storage & Handling

As they are super light and portable, 100mm Celotex boards can also be handled and transported easily; making them a doddle to install. If you need to store 100mm Celotex insulation boards for a while before installation, you should choose a cool, dry space.

Our rule of thumb when it comes to storage is that the boards should not be stored on the ground. Instead, pop them on a level surface and under a protective cover, just for good measure.

About Celotex

Celotex is a leading British manufacturer of 100mm PIR insulation. Founded in the early 1920s, the company has since evolved from a fibreboard insulation company to one that solely focuses on PIR insulation boards.

The GA4100 insulation board is just one of many popular thermal insulation solutions in the Celotex product range. It comes from the GA4000 product group, which includes 6 other thicknesses; 

What the pros say about 100mm Celotex…

Celotex 100mm is just about the most common insulation product in the UK. The term “commodity” doesn’t even come close. Its enduring popularity is due in most part to its high level of thermal efficiency balanced with its reasonable price, making it both efficient and affordable, unlike more premium products like phenolic (more expensive) or cheaper products like fibreglass (less thermally efficient).


Although Celotex will claim superiority over other manufacturers, Celotex PIR insulation is really no different to the PIR boards made by the likes of EcoTherm, Recticel and Kingspan (it’s a crowded market). As a commodity product that is heavily dependent on one central ingredient (MDI), its price is prone to sharp fluctuations in response to supply and demand. This presents a cost forecasting nightmare for builders and buyers; not helped by the fact that this product is installed in pretty much every house in the United Kingdom.


Like it or loath it, 100mm Celotex is here to stay.


5/5 based on 32 reviews Leave a Review

I used this in a suspended floor at home. It took a bit of time for me to fully install, but the boards are simple to cut and slide relatively easily in-between the beams. It's a good product and I'd recommend it.

Kris W on

Great board and great service. I'll buy again

Gene Krupps on

Good product for the job

Peter Scrills on

Managed to get a good rate after I spoke with someone over the phone

Michal V on

Not the first time I've this from these guys, and won't be the last. Spot on every time.

Gaz Long on

Boards are lightweight to move around the job

Luke Wheeler on

Used this under some floorboards, simple to handle and install.

Jay Cross on

Managed to grab this at a good price compared to other websites

John A on

The delivery driver was really nice when he dropped the boards off

Vivian K on

I used this in my roof rafters ahead of the winter

Julia Finn on

5 star product. Service was great as well

Harry D on

Excellent service and board

Jess L on

Came as expected and easier to cut with a hand saw than I first thought

Len Hill on

On time and customer service was good to help resolve a small issue

Simon C on

Top service. The boards came on time for my project

Barry G on

light and simple insulation to work with

Hank P on

Used this is in a partition wall and found them easy to cut. Delivered quick, with a cheap price

Sal Smith on

arrived as described and expected

Gerry Hall on

These easily slid in under the boards of my ground floors

Ian Frutton on

Thanks - came on time for my work

Gerry Klick on

I bought these for a big timber framed floor system job, arrived on time and the customer service team were really helpful.

Joel Simmon on

Great product, easy to work with and meet all national building regulations

Jake Cullens on

Simple to install in the timber rafters for my loft conversion

Jolie P on

Competitive price, fast delivery, and good quality product. Great insulation.

Martin Chivers on

Used this product between timber joists and timber rafters and it worked wonderfully. Loft is now incredibly toasty. Shipping costs were free after £500 spend.

John Berry on

So cheap! Much cheaper than getting it at my local Travis Perkins

Colin Gurn on

My rooms were warmer after I installed the insulation

Jack H on

My rooms were warmer after I installed the insulation

Jack H on

Easy to install and manoeuvre

Kay H on

Easy to cut and fit into walls

Mark Thomas on

Excellent insulation!

Chris Shulte on

Used in steel framed systems. Great insulation board!

Travis Bluesky on

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