CELOTEX INSULATION HAS NOW GOT A DIFFERENT NAME. IT IS NOW SOPRATHERM BY SOPREMA. WHY IS THIS?
It’s a big change for the building trade, but don't worry - the product itself hasn't gone anywhere.
As of January 1, 2026, the Celotex brand name has been retired and replaced by Sopratherm. This is part of a major rebranding effort by its parent company, Soprema UK.
Why has Celotex changed names?
The move is purely strategic and follows a series of acquisitions by the French waterproofing and insulation giant, Soprema. Here is the timeline of how we got here:
2024 Acquisition: Soprema acquired a majority stake in the Celotex PIR insulation business from Saint-Gobain.
Brand Unification: Soprema had also recently bought other major UK players like YBS Insulation (2022) and Chesterfelt (2023).
The "One Stop Shop" Goal: To make things simpler for contractors and distributors, Soprema decided to retire these individual legacy names and bring everything under the single Soprema UK banner.
What does this mean for you?
In short: New name, same board. If you are looking for your usual insulation, the specifications remain identical. To make the transition easier, Soprema has kept the classic product codes:
Old Name New Name Application
Need help finding data sheets or a U-Value Calculator for the new Sopratherm range?
1. Online U-Value Calculator:
Soprema has launched a dedicated portal to replace the old Saint-Gobain/Celotex tools. It covers floors, walls, and roofs.
• Official Calculator: Soprema Thermal U-Value Calculator
• What you'll need: You can select your "Construction Build-up" (e.g., Brick Cavity Wall or Pitched Roof) and it will suggest the required Sopratherm thickness to meet current UK Building Regulations (typically targeting 0.18 to 0.15 W /m2 K for roofs).
2. Technical Data Sheets (TDS)
If you need to submit paperwork for Building Control, you should download the new Sopratherm sheets, as they contain the updated branding and CE/UKCA markings.
• Download Hub: Soprema Document Centre
• Common Search Terms: * Search "Sopratherm GA" for the standard 50 - 100mm boards.
• Search "Sopratherm CW" for cavity wall boards.
• Search "Sopratherm PL" if you are looking for the thermal laminate (plasterboard-backed) range.
Can I still buy Celotex Insulation in the UK?
At the time of writing this article, it is still feasible that some distribution depots may still have some of the Celotex branded stock left over. As this is sold through, it will then be replaced with the new stock bearing the Soprema branding.
At Buildershop UK, we still sell all the popular ranges such as TB4000, GA4000, XR4000, CW4000 & PL4000 which can all be found in the Soprema Insulation (Celotex Insulation) category. As big industry changes such as these can take a while to filter through, you will still see the individual boards referred to as Celotex for a period of time.
Soprathem summary: new name, same insulation:
New Name, Same Board: Celotex is now Sopratherm.The insulation boards you’re used to haven't changed—only the logo on the foil has. Since Soprema UK took over, Celotex has been renamed Sopratherm.
Same Performance: All fire ratings and U-values stay the same.
Same Install: Cut it, fix it, and tape it exactly like you did before.
Same Codes: You’ll still see familiar codes like GA4000 and XR4000. It’s the same trusted PIR board, just under a new banner.
Hopefully you find the above a comprehensive guide to the rebranding. As always though, if you do have any further questions, please don't hesitate to get in touch.
