Expanded cork

We supply expanded cork boards in a range of thicknesses from 10mm up to 300mm and also expanded cork granules in a range of different granule sizes. Expanded cork is made from cork that is too resinous to be used for wine corks and is surely the most environmentally friendly insulation material on the planet.

expanded cork

The abundance of naturally occurring resins that are to be found in the cork bark made to use expanded cork are used to bind granules under pressure without using any additional adhesives. The cork is stripped from the tree every nine years (this process does no harm to the tree) and is granulated and placed in an autoclave. Then super-heated steam is added which releases the resins held within the cork granules and this resin serves as the adhesive to bind the granules together. Blocks that are sized 100x50x30cm are produced, which are cut down to make boards of the thickness required.

expanded cork granules

Here are shown expanded cork granules, which can be added to cement to make it more lightweight and with better insulating properties as well as being an insulating filler for cavities.

The technical characteristics of expanded cork are:
Thermal conductivity coefficient – 0.040 W/m.K
Density – 105-125 Kg/m3 (7.0 – 7.5 pounds per cubic foot)
Tension to stress – 1.4-2.0 KGf/cm2
Functional temperature range – -180ºc to +140ºc
Fire class – Euroclass E
R value – 3.6 per inch
Compressive strength – 15 psi
Moisture permeability – 2.2 perms at 40mm

You can see our expanded cork board prices here and there is information on non-expanded coarse granule cork insulation boards here. We also have available prices for expanded cork granules, for different size expanded cork granules.

You can download expanded cork technical data here.