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70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)

70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
  • 70mm Unilin Thin-R PLUS XT/CWP (T&G) Partial Fill Cavity Wall Insulation
  • Reduced the Thermal Bridging and improved the U-Value of the wall
  • Low emissivity foil facing on XT/CWP improves the thermal performance
  • Recommended residual cavity width is 50mm (Building Regulations)
  • Most effective method of preventing wind-driven rain penetrating a wall
Estimated delivery:
In Stock
£ 107.82
Ex VAT: £ 89.85
  • Brand: Unilin Insulation (UK) known as Xtratherm
  • Model: 70mm Unilin XT/CWP (T&G)
  • Weight: 6.00kg
  • Dimensions: 1,200mm x 450mm x 70mm
  • SKU: 70mm Unilin XT/CWP (T&G)
  • Product code: P1-3386
  • MPN: 70mm Unilin XT/CWP (T&G)

Options available

70mm Unilin XT/CWP (T&G) Thin-R Plus Cavity Walls is the best insulation solution when building traditional masonry walls to the highest thermal standards whilst maintaining a residual cavity.

The lower lambda (thermal conductivity) of 0.021 W/mK improves U-Values of the cavity and meets Future Homes standards, proving an excellent choice for passive and low energy builds.

The Cavity Wall Thin-R Plus XT/CWP tongue and groove jointing offers a practical on-site solution that results in a more robust continuous layer of cavity wall insulation.

Partial Fill Cavity Wall Plus T&G builds to a system thanks to its engineered tongue and grooved joints and pre-formed corners, ensuring insulation continuity and minimisation of thermal bridging.

XT/CWP (T&G) is the best solution when building traditional masonry walls to the highest thermal standards whilst maintaining a residual cavity, offering excellent protection from wind driven rain.

The low emissivity foil facing on the boards improves the thermal performance of the wall.

The residual cavity offers an effective method of preventing wind-driven rain penetrating a wall from the outside.

A residual cavity is the air space that remains when Cavity Wall Plus is placed against the inner leaf of the cavity of a wall.

The recommended residual cavity width allowed is 50mm in accordance with BBA Agrément certification.




Thickness: 70mm

Length: 1200mm

Width: 450mm

Size: 70mm x 450mm x 1200mm

Board coverage: 0.54m2

Pack coverage:3.24m2

Pack quantity: 6 sheets

Density (Foam Core): 30Kg/m3

Thermal Conductivity: 0.021 W/mk

R-Value: 3.30 m2K/W

Commpressive Strength: >120 (kPa)

Water Vapour Resistivity: >100 MNs/gm

Reaction to fire: NPD


Unilin XT/CWP Thin-R Plus Cavity Features:

 · Improved lambda value of 0.021 W/mK.

 · Robust tongue & groove jointing.

 · Reduced thermal bridging.

 · Clear cavity maintained.

 · No exposure restrictions.

 · Suitable for passive and low energy builds.

 · Partial fill cavity wall systems.

 · Rigid enhanced premium polyisocyanurate core.

 · Low emissivity aluminium foil facings.

 · BBA Agrément certification.


Unilin XT/CWP Thin-R Plus Cavity Insulation Installation Guidelines:

 · Under Eurocode PD 6697:2019 to BS EN 1996-1-1 and BS EN 1996-2, it is recommended that no more than four courses of block are laid on the preceding skin before installation of the insulation.

 · This allows for wall ties to be inserted accurately and without bending and thus distorting the physical characteristics of the wall ties.

 · Ensure the wall is level and free of any protrusions before installing the insulation with all edges tightly interlocked.

 · Mortar should be struck from the inner cavity face of the block to ensure mortar squeeze is minimised on the cavity side.

 · The two courses of blockwork can then be built, ensuring the mortar is struck back from the cavity face to prevent mortar squeeze.

 · Insert wall ties maximum 600mm centres one block course below DPC.

 · Wall ties should incorporate retaining clips, be Agrément approved and conform to BS EN 845-1: 2013 + A1: 2016.

 · Secure cavity boards tight against inner leaf with retaining clip on wall ties.

 · Boards should be installed with the tongue uppermost and joints should be tightly butted.

 · Ensure a minimum 150mm overlap with the floor insulation.

 · The receiving block should be plumb to provide a flat surface to accept the insulation.

 · As with setting out, installation should commence from adjacent corners using the Cavity Wall Plus pre-formed corner boards.

 · Alternate corner boards will achieve the offset break bonded pattern for the insulation.

 · Maintain a 50mm residual cavity to suit all exposure zones.

 · In isolated circumstances, where the cavity is obstructed, a minimum 25mm residual cavity should always be maintained and extra consideration should be given to fixings and weatherproofing.

 · Any reduction in cavity width should be agreed with Building Control.

 · Place wall ties at maximum 900mm x 450mm centres, securing with a minimum of 3 wall ties per board.

 · Ensure block joints are fully bonded with unbroken mortar.

 · Fix wall ties 225mm vertically and 150mm horizontally from the face of unbonded jambs.

 · Ensure wall ties and cavities are kept clean of mortar.

 · Wall ties should be sloped downwards towards the outer leaf.

 · A cavity board should be used to keep the cavity clean.

 · Cavity Wall Plus corner boards and cavity closers may be fitted to provide robust detailing.

 · Newly erected masonry should be protected to prevent the mortar being washed out of the joints by rain.

 · Walls should be prevented from becoming saturated by covering the top of the wall with waterproof sheets; this is particularly important to minimise the incidence of efflorescence and lime bloom.

 · When any working platform is not in use, the inner board should be turned away from the wall to prevent the splashing of the wall face.


*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 

*Special Product - Non returnable cancelable.

Board covarage 3.24 m2
Commpressive Strength 120 (kPa)
Density 30-32 Kg/m3
Length 1200mm
Material Polyisocyanurate Rigid Foam
Profile (T&G) tongue and groove jointing
R-Value 3.30 m2K/W
Reaction to fire NPD
Size 70mm x 450mm x 1200mm
Surface spread of flame NPD
Thermal Conductivity 0.021 W/mk
Thickness 70mm
Water Vapour Resistivity 100 MNs/gm
Weight 6.00 kg
Width 450mm
Vapour Resistivity 100 MNs/gm
Finish Composite Foil Facings
Shipping method Articulated Vehicle ǀ Courier
Applications Traditional masonry walls
BBA Certified Yes (No. 08/4613)
Foil faced Both sides (aluminium)
ETA Notification Yes
Features Enhanced Performance Cavity Wall Insulation
Manufacturer Unilin Insulation®

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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.
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
70mm Unilin XT/CWP (T&G) Plus Cavity Walls (pack of 6)
£ 107.82