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Wallrock R300 Cosyliner


Wallrock Brochure DownloadWallrock R300 Cosyliner is the junior member of the Wallrock Thermally Efficient Wallpaper range being 1mm in thickness but still offers worthwhile energy savings as well as the ability to cover and reinforce poor plaster and other surfaces. All Wallrock Thermally Efficient wallpapers work to save energy from the moment heating is turned on by slowing down the rate at which a cold walls soak up heat energy - and allowing the room to warm up considerably faster creating a comfortable room environment with less energy. This effect is valuable in any home with solid walls and even those with external or cavity insulation - especially where the heating is regularily turned on and off. Once the room is warmed up and comfortable, Wallrock R300 Cosyliner goes on working producing steady energy savings.

Wallrock R300 Cosyliner also helps reduce condensation problems - as more room warmth is retained at the wall surface there is less opportunity for condensation to form on a cold wall and consequently a reduced risk of unhealthy mould growth.

The surface of Wallrock R300 Cosyliner is longlasting, durable and suitable for painting directly, although for a perfect finish we recommend cross lining with Wallrock Fibreliner (avoid the use of standard linings) which allows not only painting but the application of decorative wallpaper.

This product is suitable as a localised ‘problem solver’ for cold external walls and is not recommended for use in fire escape routes inside your home unless the surface is further treated with a fire retardant covering. This product is class C fire rated and can be used for projects such as new builds and extensions where Building regulations are applicable.

To see the product label, please click here

To see the product's Fire Certificate, please click here

Important Safety Information
Compliance with Building Regulations;
This product has a European Fire Rating class of  C S2 d0 and is compliant with Building Regulations in regard to wallpaper for residential accommodation including garages. If used purely as an insulation then the insulation value alone will be too low to meet UK Building regulations.
If the product is used as part of a system that both adds to the insulation value and protects the surface from fire it may be fully compliant but expert advice should be sought.
Fire Safety
Fire resistance can also be improved further by cross lining the surface with Wallrock Fireliner applied with Wallrock Fireliner FR Adhesive.
Surfaces painted prior to 1960 may contain lead pigments and special precautions should be taken when preparing such surfaces.

  • U Value 40 W/m²K
  • Reinforces and smooths out rough and light textured surfaces
  • Thermally efficient, reduces heat loss and room warm up times
  • Combats condensation and mould formation
  • Covers and reinforces damaged walls
  • Excellent performance on many surfaces, damaged plaster, cracked rendering, wood panelling or plasterboard*
  • Paste the wall or the paper
  • Allows walls to breathe
  • Contains No PVC Or Glassfibre
  • Long service life
  • Fire rated EN class C-s2,d0 when applied to non combustible mineral base surface
  • Can be painted or overhung with ‘paste the wall’ wallpapers
  • Apply with Wallrock® Thermal Liner Adhesive or Wallrock® Thermal FR (Fire Retardant) Adhesive is recommended

single length: 10m x 75cm coverage: 7.5m² approx
double length: 25m x 100cm coverage: 25m² approx


  1. Ensure base surfaces are clean, dry, firm and free from any loose or flaking material. Wallrock R300 Cosyliner can also be applied in some circumstances directly over cracked and light to medium textured surfaces which are firmly adhered and stable - in such cases it is always advisable to cover a small test area before continuing.
  2. Size or seal absorbant surfaces. Apply the Wallrock Thermal Liner Adhesive generously to the wall using a roller. In difficult to reach corners use a brush or spatula. On textured or damaged surfaces it is especially important to apply a generous layer of adhesive. Apply enough adhesive to apply one length of Wallrock R300 Cosyliner at a time ensuring the pasted area exceeds the width of the Wallrock R300 Cosyliner(see paste consumption guide).
  3. Always apply Wallrock R300 Cosyliner with the smooth face to the outside, furry side to the wall. Apply Wallrock R300 Cosyliner directly from the roll onto the wet adhesive and slide into place. Smooth out any bubbles with a roller or similar. Leave a small amount of surplus material for trimming where necessary.
  4. Cut off any excess Wallrock R300 Cosyliner at the ceiling, floors and corners using a good quality trimming knife in combination with a suitable guide. Alternatively carefully mark the Wallrock R300 Cosyliner using a pencil and trim with good quality decorators scissors.
  5. Allow at least 24 hours for drying, longer if conditions are especially humid or cold. Wherever possible we also recommend that the Wallrock R300 Cosyliner is allowed to dry out naturally and any heating is turned off. However if temperatures are below 10°c/50°F it is advisable that low level heating is used to ensure that the adhesive can cure effectively.
  6. Any small gaps at seams and corners should be filled and sanded. Always use a good quality filler that has minimal shrinkage and flexibility.
  7. On external corners a corner profile can be used to cover the corner or use flexible filler to fill the open edge of the Wallrock R300 Cosyliner.
  8. The surface of Wallrock R300 Cosyliner can be painted directly using emulsion paint (flat interior latex paint). If you intend painting the surface the finish can be further improved by overlining the Wallrock R300 Cosyliner with a dimensionally stable lining such as Wallrock Fibreliner (or similar Paste-The-Wall lining). If over hanging with decorative wallpaper we recommend using a ‘Paste-The-Wall’ type. Should you want to use a traditional paper we recommend overlining the Cosy Liner with Wallrock Fibreliner (or similar Paste-The-Wall lining) before proceeding.


Typical paste consumption guide:
3-3.5kg of adhesive per roll of the 10m x 0.75m, whereas the 25m x 1.0m roll will require approx 10-11Kg per roll, The adhesive consumption indication is for guidance only, on walls in good condition less paste may be required whereas on damaged or textured walls and surfaces that are not vertical, more paste may be required.

To minimise the hazard in the event of fire, do not apply wallcoverings over expanded polystyrene veneers and ensure the wallcoverings are always firmly stuck down as loose wallcoverings may contribute to the hazard. Surfaces painted prior to 1960 may contain lead pigments and special precautions should be taken when preparing these surfaces.


This is a simple wallpaper calculator and should be used as a guide only. You can find the roll width and roll length you are after on the specific product page.
Roll widths are provided in meters (such as 0.5 x 10mtr) so your wall widths and heights should be inputted in meters also.
If you are purchasing an offset match product then you may need a little extra as there may be some waste. If you have any windows or doors in your walls you can simply ignore these. This will give a good estimate of required roll numbers.

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