Supafil CarbonPlus

blow in insulationSupafil® CarbonPlus is especially designed for installation into existing double brick masonry cavities by an Approved Installer.

Supafil CarbonPlus is an unbonded, silicone treated, non-combustible glass mineral wool product which requires no mixing on site.

It is ideal to increase the energy efficiency in older homes for which it is impossible to install batts.

In the United Kingdom, this double brick wall insulation has been installed in over 5 million existing homes to increase energy efficiency and bring the comfort levels up to modern standards.


Supafil CarbonPlus is specifically designed to be used in existing masonry cavity walls with a minumim cavity width of 40mm.

  • Suitable for new-build or retrofit
  • Quick and clean to install
  • Installed by approved contractors
  • Low cost
  • Injected after wall constructed, allowing empty cavity to be checked before installation

Supafil CarbonPlus 

Product R-Weight per bale (kg) Installed Density (kg/m³)  Thermal Conductivity Cavity Width (mm) Delcared thermal resistance R-Value (m²K/W) Minimum bag usage rate
Supafil CarbonPlus 15.5 25 0.039 50 R1.3 8 bags/100

Code Mark SupaFil                  


Code Mark SupaFilCodeMark certification for Supafil CarbonPlus approves the application and installation procedure for this product. The product is for use in existing masonry cavity walls, subject to the conditions detailed in CodeMark certificate 30057.

Specification Guide

The cavity wall insulation shall be Supafil CarbonPlus 0.038 W/mK, 25kg/m3, CodeMark certified to meet the provisions of the BCA. The product will be non-combustible, CFC/HCFC free, zero ODP and GWP, silicone treated glasswool insulation with high post-consumer recycled glass content. It will be manufactured under Quality Assurance Standards ISO 9001:2008 and ISO 14001:2004 by Knauf Insulation and shall be installed in accordance with the instructions issued by them.

Vapour resistance - resistivity

Supafil CarbonPlus offers negligible resistance to the passage of water vapour and has a vapour resistivity of 5.00 MN.s.g.m.

Moisture resistance

Tests by the British Board of Agrément confirm that Supafil CarbonPlus will not transmit water to the inner leaf. Nor will it transmit moisture by capillary action across the cavity or from below damp proof course level. This has been confirmed by independent research conducted for the Energy Saving Trust (UK), which shows that Supafil CarbonPlus does not add to the risk of water penetration.

Handling and storage

Supafil CarbonPlus is supplied in polythene packs which are designed for short term protection only. For longer term protection on site, the product should either be stored indoors, or under cover and off the ground. Supafil CarbonPlus should not be left permanently exposed to the elements.

Supafil CarbonPlus is to be installed by an approved installer, please contact us for further details here