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25mm Celotex TB4000 PIR Insulation Board ǀ TB4025

25mm Celotex TB4000 PIR Rigid Foam Insulation Board (TB4025)
25mm Celotex TB4000 PIR Insulation Board ǀ TB4025
  • Size: 2400mm x 1200mm
  • Board covarage: 2.88m2
  • Thermal Conductivity: 0.022 W/mk
  • Surface spread of flame: Class 1
  • BBA Approved (Cert no 17/5405, 16/5352)
Estimated delivery:
In Stock
£ 37.76
Ex VAT: £ 31.47
  • Brand: Celotex®
  • Model: 25mm TB4000
  • Weight: 3.38kg
  • Dimensions: 2,400mm x 1,200mm x 25mm
  • SKU: 25mm
  • Product code: P1-628
  • MPN: 25mm Celotex TB4025

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This product has a minimum quantity of 10

25mm Celotex TB4000 PIR Insulation Board (TB4025) is an easy to cut and install multi-purpose polyisocyanurate (PIR) rigid foam insulation board featuring a low emissivity foil facings that is suitable for floor, wall, ceiling and roof cut-to-fit applications.

Celotex Insulation Board is an excellent high-performance thermal insulation material with a thermal conductivity as low as 0.022 W/m.K which helps to reduce the thickness of insulation required to hit the target U-values.

TB4025 Celotex Insulation has been assessed by the BBA for its defined applications and compliance with the relevant Building Regulations. 

PIR boards by Celotex enhance space in the construction design and help to reduce the heating and cooling costs within the building.

Celotex boards are versatile and available in a wide range of thicknesses from 12mm to 200mm (TB4000, GA4000 and XR4000).

TB4000 will help you to meet the requirements of UK thermal building regulations.

Celotex PIR rigid insulation boards can be readily cut using a sharp knife.




Thickness: 25mm

Size: 1200mm x 2400mm

Board covarage: 2.88m2

Density (Foam Core): 30-32 Kg/m3

Thermal Conductivity: 0.022 W/mk

R-Value: 1.136m2K/W

Commpressive Strength: >120 kPa

Water Vapour Resistivity: >100 MNs/gm

Surface spread of flame: Class 1

Reaction to fire: Euroclass E Reaction to Fire classification, according to EN 13501-1


Product Benefits:

 · Excellent thermal conductivity - Lambda value of 0.022 W/mK

 · Low emissivity foil facing provides improved thermal performance in cavity air spaces, reducing the achieved U-value

 · Easy to install – lightweight boards are straightforward to handle, fit and transport

 · BBA certification - third-party verification that the product has been assessed for it's defined applications and is compliant with the relevant Building Regulations.



 · Ground floors – perimeter upstand

 · External walls – internal lining

 · Pitched roofs – underneath the rafters

 · Flat roof - between and under joists


Product Features:

 · Low emissivity foil facing

 · Lightweight 2400mm x 1200mm boards

 · Achieves a BRE Green Guide A rating

 · BBA approved – certificates 16/5352, 17/5405



 · BBA Approved (Cert no 17/5405, 16/5352) for floors, dry lining, pitched roof and timber frame applications. 

 · CE Marked (18.DOPTB4000-01) to BS EN 13165.

 · Quality Management Standard – ISO 9001:2015

 · Environmental Management System – ISO 14001:2015


*Further information may be found in our Downloads section.

Fairly easy access to all PDF files.

Datasheet ǀ Declaration of Performance - DoP ǀ BBA Certificate ǀ Installation Guide ǀ Certificates ǀ Brochure ǀ SPEC Sheet 

Board covarage 2.88 m2
Density 30-32 Kg/m3
Length 2400mm
Material Polyisocyanurate (PIR)
Profile Improved thermal performance
Reaction to fire Euroclass E
Surface spread of flame Class 1
Thermal Conductivity 0.022 W/mk
Thickness 25mm
Water Vapour Resistivity 100 MNs/gm
Width 1200mm
Vapour Resistivity 100 MNs/gm
Building Regulations Compliant
Finish Aluminium Foil Facings
Shipping method Articulated Vehicle
Applications Roofs ǀ Walls ǀ Floors ǀ Ceilings
Vapour Control Layer Yes, build in
ETA Notification Yes
Features High-performance Rigid Insulation
Manufacturer Celotex TB4000®

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We deliver insulation materials to Mainland UK only. Deliveries to Highlands, Northern Ireland, Isle of Wight etc.. might be possible at additional cost.
We offer free delivery on most of the orders above £300 (excluding VAT) (except special products - shipping cost via courier - products marked ''Request A Quote'')

Delivery of some insulation materials might be extended due to the current situation (Covid-19, stock shortages, allocations).
If you need materials quickly please contact us - we will do our best to help you source materials needed.

We do not deliver on weekends and bank holidays. Sometimes we can deliver on Saturdays - please check with us before placing the order.
If you need any further information please contact us tel. 02081910776

We can help to calculate price per m2 or linear meter (one meter in length) cost, please just contact us via phone 02081910776, email or live chat. Alternatively, you can work it out yourself quickly and easily: to get cost per meter square please divide price shown in orange area by ''Required area (m2)'' Example price of £28.80 divided by board coverage 2.88m2 = cost of £10.00 per m2.


No matter whether you choose a local installer or a national company, there’s a few tips to help you find the right installer for your home insulation improvements, such as asking for recommendations and making sure that they’re part of a certification scheme. This makes sure that they have the right skills and standards of workmanship to carry out the installation, and you can be sure that they know exactly what they are doing.


1. Thermal inspection picture in portfolio

It’s worth seeing a installer’s previous work. There’s no harm asking if you can see any properties nearby that they’ve installed insulation in. Best way would be to see Infrared Thermal Imaging Inspections. Thermal cameras spot small, but key changes in temperature in different areas of a house, identifying problematic areas that the human eye never could and some that a visual inspection could only hypothesize.

2. Reviews

Along with checking recommendations and previous work, finding reviews online can often be a great way to find out if they provide a good service or not. However, it’s best not to solely rely on reviews you may find or review websites, as there’s no controlling who writes them.

3. Compare prices

Comparing prices will also ensure companies can’t take advantage of you and give you a fair price. 

4. Word of Mouth

The best way to find a great insulation installer is through recommendations. Make sure you ask friends and family. They will most likely give you their honest opinion and can tell you from first hand experience.


Whether you require a wall, cladding, external wall, loft or floor insulation fitted, you can find and hire your local insulation installers from popular UK web pages. A simple internet search will return thousands of potential installers near your area.



We are the stockist of construction materials and related products for both trade and DIY from most recognizable brands in the UK like Cordek, RCM, Promat, Rockwool, Isover, Celotex, Xtratherm, Ursa, Low-E, Cedral, Kingspan, Dufaylite, British Gypsum, K-rend, Ecotherm, Iko enertherm, Kay-Metzeler, Terrawool to allow you to complete your insulation job on time at competitive prices and the highest standards.


Whether you are a large company or a DIYer, if you need a large amount of insulation materials, we can offer quantity discounts at the best prices. Please contact us and our friendly customer service will try to find the best and cheapest solutions for you. We value your time and we will try to deliver the products as soon as possible at a reasonable price to your construction site or house. The UK's leading insulation supplier near you and your needs. Price List available upon request.
25mm Celotex TB4000 PIR Rigid Foam Insulation Board (TB4025)
25mm Celotex TB4000 PIR Insulation Board ǀ TB4025
£ 37.76