Celotex CW4000 Cavity Wall Insulation Board

From £72.16 £60.13
In stock
Only %1 left
Celotex CW4000 Cavity Wall Insulation Board
Product Description

Celotex CW4000 is a partial fill cavity wall insulation board. This easy-to-install polyisocyanurate (PIR) board offers exceptional thermal performance and consists of a low emissivity foil facing.

Size: 1200mm x 450mm


size: 1200mm x 450mm
pack size:

We are happy to help with enquiries, stock availability or any technical help you require, however for security reasons we cannot take orders over the phone. So if you need to chat give us a call on 03301231761 or email us at [email protected].

What is Celotex CW4000 Cavity Wall Insulation Board? 

Celotex CW4000 is a versatile insulation material with PIR foam and insulation core, delivering thermal conductivity of 0.022 W/mK. CW4000 is specifically designed for the cavity and optimum thermal performance. 

It is important to protect your hands against sharp edges while handling this product by wearing protective gloves. You should also wear a dust mask and safety glasses when cutting and drilling to protect your respiratory system.


Features and benefits of Celotex CW4000 Cavity Wall Insulation Board: 


  • Excellent thermal performance with a thermal conductivity of 0.022 W/m.K.
  • Low emissivity foil facing provides improved thermal performance in sealed cavity air spaces, improving the achievable U-value.
  • Easy to install – light and rigid which assists with ease of transportation, handling, and fitting.
  • BBA certified – assessed by the BBA as fit for use in defined partial fill cavity wall applications if installed, used, and maintained as set out in the certificate.
  • Celotex CW4000 achieves a BRE Green Guide Rating of A.
  • Board/roll size: width 450mm, length 1200mm
  • Thickness: 40-100mm
  • Material: PIR

Applications for Celotex CW4000 Cavity Wall Insulation Board: 


  • External Walls – partial fill cavity wall

Read more on the applications of Celotex insulation boards

Data Sheet (166.17 kB)
Safety Data Sheet (619.33 kB)
Customer Questions
What is the difference between CW4000 and GA4000 Celotex?
Both the Celotex CW4000 and GA4000 (as well as TB4000 & XR4000) are made from the the same insulation material, but are made for different applications. The CW4000 is for use in partial fill cavity wall applications and is supplied in smaller sheet sizes at 1200mm x 450mm (0.54m2), to fit standard wall tie spacing for ease of installation.
Does this have the same thermal properties as standard Celotex?
The Celotex CW4000 and GA4000 range have the same excellent thermal performance with a thermal conductivity of 0.022 W/m.K. Both boards have a low emissivity foil facing with the differnce being CW4000 sheets are smaller for use in a partial fill cavity. 
What size are the boards and are these sold in packs?
Celotex CW4000 is supplied in sheet sizes of 1200mm x 450mm (0.54m2) and are sold in pack quantities. The number of sheets in a pack will depend on the thickness of the sheet.
Can you fit 100mm CW4000 Celotex directly to a new plasterboard wall?
We advise that the CW4000 range is not installed on the internal side of the wall as this product is only designed and tested as a partial fill cavity wall insulation.
Did you find what you were looking for?
More Information
SKUCelotex CW4000 Cavity Wall Insulation Board
Supplier Part NumberCW4000
Size450mm x 1200mm

Orders and Delivery

Free delivery if your order is over £300 ex VAT. Orders between £100 - £300 ex VAT will be subject to a delivery charge of £50 ex VAT. Please note, we are unable to accept orders less than £100 ex VAT

When ordering on line you can specify the date of delivery, however we would not be able to specify the time of delivery on that day.

• Please note that we have a number of large vehicles, including articulated vehicles that may be used for delivery. Please advise us in the comments on your order if access to the delivery address is limited.

• Due to insurance guidelines, delivery personnel are unable to enter private residences. Delivery will be as far as possible to the kerbside of the delivery address. The recipient of the products is responsible for any additional lifting once the delivery has been made. Please bear in mind that Insulation products can be bulky and / or heavy.

• The delivery driver will require a signature to confirm the goods have been received.

 † Unfortunately we, Insulation Express, cannot deliver to the Highlands & Islands of the UK. However we will be happy to deliver to a freight forwarding company on your behalf.


Returns and Refunds

In the unlikely event that you need to return an item, please contact our team on [email protected] within 14 days of accepting delivery of the item.

Restocking charges may apply. We will discuss this with you upon receipt of the cancellation request. Restocking charges will be applied where the products are no longer required AND NOT for goods returned because either defective or damaged.

We usually charge 30% of value (minimum £25.00).

Please note that we cannot accept returns on special orders. Special orders may consist of items sent via third party shipping companies or made to measure products. If you are unsure on whether or not your item is a special order, please contact us on [email protected] prior to placing the order.

Write Your Own Review
You're reviewing:Celotex CW4000 Cavity Wall Insulation Board

Free delivery on orders over £300! Terms and Conditions apply

For all your roofing needs

Check out our new website!

 Buy Power tools online