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50mm Xtratherm Xtroliner XO/CW Cavity Insulation Board ǀ pack of 9

50mm Xtratherm XO/CW T&G Premium PIR Insulation - Partial Fill Cavity (pack of 9)
50mm Xtratherm XO/CW T&G Premium PIR Insulation - Partial Fill Cavity (pack of 9)
50mm Xtratherm XO/CW T&G Premium PIR Insulation - Partial Fill Cavity (pack of 9)
50mm Xtratherm XO/CW T&G Premium PIR Insulation - Partial Fill Cavity (pack of 9)
50mm Xtratherm Xtroliner XO/CW Cavity Insulation Board ǀ pack of 9
  • A + rating under the BRE Green Guide
  • Thermal Conductivity: 0.021W/mK
  • Reaction to Fire Euroclass C-s1, d0
  • (T&G) tongue and groove jointing
  • BBA Certificate 12/4956 - Building Regulations
Estimated delivery:
In Stock
£ 132.14
Ex VAT: £ 110.12
  • Brand: Xtratherm®
  • Model: 50mm XO/CW
  • Dimensions: 1,200mm x 450mm x 50mm
  • SKU: 50mm XO/CW
  • Product code: P1-1774
  • MPN: XO/CW T&G

Options available

50mm Xtratherm Xtroliner XO/CW is an improved performance PIR (polyisocyanurate) tongue and groove insulation board with robust foil facings designed for partial fill cavity wall insulation with an approved thermal conductivity (lambda value) as low as 0.021W/mK.

This lower lambda improves U-Values and meets Zero Carbon standards, proving an excellent choice for passive and low energy builds.

XO/CW T&G can achieve a passive U-Value of 0.15 W/m2K in a traditional cavity wall asked for in the Building Regulations.

Using XO/CW (T&G), a residual cavity is maintained, offering excellent protection against wind driven rain.

The robust foil facings on both sides of the XO/CW board incorporate an integral vapour barrier, which helps to reduce the risk of condensation.

Using XO/CW will reduce heat loss while also delivering excellent thermal bridging details.

Xtratherm Xtroliner products are stable, rot proof and will remain effective for the life span of the building (depending on specification and installation).

The polyisocyanurate foam insulation boards can be readily cut using a sharp knife or fine toothed saw.

When it comes to health and safety, Xtratherm boards are chemically inert and safe to use.




Width: 450mm

Length: 1200mm

Pack Quantity: 9

Pack Coverage: 4.86m2

Profile: Tongue and Groove

R-Value: 2.35m2K/W

Thermal Conductivity: 0.021W/mK

Compressive Strength: >120 (kPa)

Reaction to Fire Euroclass: C-s2, d0


Key points:

 · Robust foil facings.

 · BBA Certified.

 · High compressive strength >120 (kPa).

 · Superior performance rigid PIR insulation.

 · Euroclass C-s2, d0 enhanced fire classification.

 · Thermal conductivity of 0.021 W/mK.

 · Reduced thermal bridging details.

 · Reduced risk of condensation.

 · Lightweight and easy to install.

 · Integral vapour control layer.

 · Reduced insulation thickness.

 · Lower lambda values for improved U-values.


Handling, Cutting and Storage:

 · Xtratherm insulation should be stored off the ground, on a clean flat surface and must be stored under cover.

 · The polythene wrapping is not considered adequate protection for outside exposure. 

 · Care should be taken to protect the insulation in storage and during the build process.

 · Appropriate PPE should be worn when handling insulation.


Certification and standards:

 · BBA Certification No.12/4956.

 · BS EN ISO 9001 Quality Management System.

 · BS EN ISO 14001 Environmental Management System.

 · BS EN 13165.


*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 4.86 m2
Length 1200mm
Material PIR (polyisocyanurate)
Pack Coverage 4.86m2
Pack Quantity 9
Profile Tongue and Groove
R-Value 2.35m2K/W
Thermal Conductivity 0.021W/mK
Width 450mm
Fire Classification Euroclass C-s2, d0
BRE Green Guide Rating A+ rating
Building Regulations Compatible
Coverage 4.86m2
Finish Robust foil
Quantity 9
Shipping method Articulated Vehicle ǀ Courier
Applications Partial fill cavity wall insulation
BBA Certified Yes (no. 12/4956)
ETA Notification Yes
Features Lower lambda improves U-Values
Manufacturer Xtratherm Xtroliner®

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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.
50mm Xtratherm XO/CW T&G Premium PIR Insulation - Partial Fill Cavity (pack of 9)
50mm Xtratherm Xtroliner XO/CW Cavity Insulation Board ǀ pack of 9
£ 132.14