Wallrock Cosy Liner KV300

Since 2013

  • Brand: Wallrock
  • Style: Foundations

    Product Overview

    Wallrock Cosy Liner is an economical and effective member of the Wallrock family, offering worthwhile energy savings and faster room warm up times as well as the ability to fight condensation and the formation of mound. Unlike many products, it also allows your walls to breathe.
    Cosy Liner has a hard wearing, textile reinforced surface and is thick enough to soak up some larger surface imperfections - ideal for permanently covering and reinforcing light textures, cracked and damaged plaster, plasterboard, poor rendering and a host of other problem surfaces.

    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.

    Wallrock Cosy Liner is part of the Thermally Efficient Wallper range. Please click on the PDF file below to find out more.



    • Energy saving
    • Fast room 'warm up'
    • Combats condensation and mould
    • Covers and reinforces damaged walls
    • Smooths out light textures
    • Allows walls to breathe
    • Contains no PVC or glass fibre
    • Long service life
    • Fire Rating : EN C


  • Roll Size (m): 0.75 x 10
  • Coverage (m²): 7.5
  • Pattern Repeat (cm): 0
  • Carton Quantity: 2 Rolls
  • Recommended Adhesive(s):
    We strongly recommend using our Wallrock Thermal Liner Adhesive for application of this durable heavy duty product.

  • BBA Certification (British Board of Agrement):
  • Fire Certification:
  • Wallrock Cosy Liner KV300
  • Assessment of insulation products are reviewed in 3 ways;

    1. The efficiency measurement of an actual material is called the Lambda. The higher the Lambda rating the more efficient it is and as a result will require less energy or heat to feel warm an cosy. This rating is measures in Watts / Meter x Kelvin.
    2. Another aspect is the thermal resistance (R), a measurement of how well a material resists the transfer of heat. This takes into account the thickness and the material's ingredients. The higher the rating the more resilient the material is, retaining the heat rather than allowing it to waste away. The measurement units are meters squared x Kelvin/Watts.
    3. Thermal transmittance (U) is the exact opposite of thermal resistance. This measurement is how easily a material conducts heat, so the lower the number the smaller of amount of energy or heat will be lost. This is measure in Watts/mtr2 x Kelvin
    4. Reviewing The Thermal Liner Energy Savings

    With these 3 measurements the energy savings can be worked out once the room is up to a constant steady temperature. The advantage of using thermal liner is that its heat saving properties will allow a room to get to a steady working temperature as it retains more heat. So in real life the savings will be greater, precisely how much will depend on the outside temperature, wall thickness and construction plus how many times the heating is switched on and off.

    • A typical U value of a plastered solid brick wall is 2.1 Watts/mtr2 K
    • Therefore the R value is 1/2.1 = 0.476m2 K/W
    • The BBA certificate for Thermal liner states an R value of 0.0821 mtr2 K/W
    • The total R value for the wall with thermal liner is 0.476 + 0.0821 = 0.5581mtr2 K/W
    • This can be converted back to a U value; 1/ 0.5581 = l.79 W/mtr2K
    • As a result by applying Wallrock Thermal Liner to solid walls the U value is reduced from 2.1 to 1.79 W/mtr2 K
    In conclusion, by applying Wallrock Thermal Liner to a solid wall the standing heat loss can be reduced by 15%.
  • Condensation forms on walls when room air at a significantly different temperature comes into contact with them, in much the same way as condensation forms on a glass containing a cool drink.

    Condensation helps to create the perfect breeding ground for unhealthy mould spores to grow and flourish with the tell-tale black growth often forming in the coldest areas of the room such as corners and areas around windows or external doors. Mould spores can be especially hazardous to allergy sufferers.

    Thermally efficient wallpapers hold more of the heat energy from the room’s air at the wall surface helping to combat the conditions which promote condensation forming and mould growing.

  • Follow the instructions and apply the liner directly to a surface pre-coated with Thermal Liner Adhesive.

    Once dry, any gaps at seams can be filled with flexible filler and the surface painted.

    Alternatively, wallpaper can be applied directly to the surface. We strongly recommend a ‘Paste-The-Wall’ type of wallpaper.

    Please take a look at the video above for a full application example of Wallrock Thermal Liner.


  • Corringham Road, Gainsborough
    Lincolnshire, DN21 1QB

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