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75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)

75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
  • 75mm Unilin SR/CW Phenolic Insulation Board for Partial Fill Cavity Walls
  • Safe-R SR/CW improves U-Values and meets Future Homes standards
  • SR/CW Providing an excellent choice for passive and low energy builds
  • Can achieve a passive U-Value of 0.15 W/m2K in a traditional cavity wall
  • Lambda (thermal conductivity) of 0.020 W/mK and Euroclass D-s1 d0
Estimated delivery:
In Stock
£ 117.00
Ex VAT: £ 97.50
  • Brand: Unilin Insulation (UK) known as Xtratherm
  • Model: 75mm Unilin SR/CW Cavity Walls
  • Weight: 8.00kg
  • Dimensions: 1,200mm x 450mm x 75mm
  • SKU: 75mm Unilin SR/CW Cavity Walls
  • Product code: P1-3511
  • MPN: 75mm Unilin SR/CW Cavity Walls

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75mm Unilin SR/CW is used as a partial fill insulation in external cavity walls with masonry inner and outer leaves, in new domestic and commercial buildings, offering protection from wind driven rain.

Unilin Safe-R SR/CW is manufactured to EN 13166 by Unilin Insulation with certified lambda (thermal conductivity) of 0.020 W/mK and Euroclass D-s1 d0 fire classification.

SR/CW partial fill cavity wall insulation is the solution of choice to achieve the lower U-Values asked for under the building regulations whilst maintaining a residual cavity as a protection from wind driven rain.

Partial fill masonry walls are the predominant construction method for traditional buildings, SR/CW phenolic insulation offers a solution when lower U-Values are demanded.

The high performance to thickness ratio of SR/CW allows for excellent U-Values to be achieved within traditional constructions without dramatically increasing the overall width of the wall.

Using SR/CW allows the residual cavity to be maintained, providing an effective method of preventing moisture ingress.

SR/CW is durable, rot proof and sufficiently stable to remain effective as cavity insulation for the life of the building.

Unilin Safe-R SR/CW is a cheaper alternative to Kingspan Kooltherm K108 Cavity Board.

The recommended residual cavity width required is 50mm in accordance with BBA agrément certification.




Thickness: 75mm

Width: 450mm

Length: 1200mm

Size: 75mm x 450mm x 1200mm

Pack Quantity: 4 sheets

Pack Coverage: 2.16m2

Board Coverage: 0.54m2

Profile: Square Edge

R-Value: 3.55 m2K/W

Density (Foam Core): 32kg/m3 

Thermal Conductivity: 0.020 W/mK

Compressive Strength: >100 (kPa)

Reaction to Fire: Euroclass D, s1-d0


Unilin SR/CW Partial Fill Cavity Features:

 · Clear cavity maintained.

 · Protection from wind driven rain.

 · Reduced insulation thickness.

 · Used for traditional masonry walls.

 · Reduced thermal bridging.

 · Provides the most efficient U-Values.

 · Effective method of preventing moisture ingress.

 · Lightweight and easy to install.

 · Meets U-values asked for in the Building Regulations.

 · Premium phenolic rigid foam insulation.

 · Suitable for new build and refurbishment projects.

 · Suitable for domestic and non-domestic buildings.

 · Certified lambda (thermal conductivity) of 0.020 W/mK.

 · Declared Euroclass D-s1 d0 fire classification.

 · Manufactured to EN 13166 by Unilin Insulation.

 · BBA Certified (certification no. 23/6884).

 · Durable, rot proof and stable.


Unilin SR/CW Partial Fill Cavity Board Installation Guidelines:

 · Blocks should be laid in accordance with relevant standards and ensure that mortar is robust enough to avoid slumping at joints and allow for the correct positioning of wall ties.

 · 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 minimized 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 and be BBA Certificate Agrément approved.

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

 · 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.

 · Stagger the board joints to create an offset brick bonded pattern.

 · 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.

 · 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.

 · ACDs must be followed to ensure that installation is in accordance with current Building Regulations and accounted for in the energy calculation.


*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 2.16 m2
Colour Light pink
Density 32 Kg/m3
Length 1200mm
Material Phenolic Rigid Foam
Pack Coverage 2.16m2
Pack Quantity 4 boards
Profile Square Edge
R-Value 3.55 m2K/W
Size 75mm x 450mm x 1200mm
Thermal Conductivity 0.020 W/mK
Thickness 75mm
Width 450mm
Fire Reaction Euroclass D, s1-d0
Coverage 0.54m2
Finish Robust aluminum foil facings
Quantity 4 sheets
Shipping method Articulated Vehicle ǀ Courier
Applications Partial Fill Cavity Walls
BBA Certified Yes (No. 23/6884)
Fixing method Mortar, Cavity Wall Ties
Foil faced Yes, foil facings on both sides
ETA Notification Yes
U-value 0.15 - 0.28 W/m²K
Features Achieve U-Values asked for under the Building Regulations
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.
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
75mm Unilin SR/CW Partial Fill Cavity Wall Board (pack of 4)
£ 117.00