Cork granules
Cork granules are a loose-fill thermal and acoustic insulation, used to fill floors, lofts or cavity walls. Made from collected and crushed corks, they put an existing material back to use with no added binder.
What are cork granules?
Loose-fill cork granulate is a thermal and acoustic insulation made of collected corks that are then crushed, with no added binder. The cork acts both as an insulating material, through the closed-cell structure of its walls, and as an absorbent material, through its flexibility. Collection turns post-consumer waste into a reusable raw material.
The material is light, breathable and unaffected by moisture. Its loose structure fills irregular cavities, and the installed thickness determines the thermal performance achieved.
It is intended for filling between joists, insulating unconverted or converted lofts, floor fill on slabs and filling vertical cavity walls.
De Vlaspit produces the granulate in Scherpenheuvel, from corks collected in Belgium and northern France. At end of life, the cork can be removed and reused on a new project or composted with biobased materials.
Installation & uses
Installation is dry, by pouring into the cavity to be insulated, keeping the material under cover until it is installed. On a floor or an open roof, a dust-proof membrane can be laid at the bottom before the granules are spread by hand or with a rake.
In a closed cavity, access requires a minimal opening to insert a blowing hose or to push the cork to the back with a brush. A vapour control layer can be installed on the inner face, depending on the wall build-up.
Mechanical blowing covers large areas quickly and reaches configurations that are hard to access, in new build as well as renovation.
At end of life, the cork can be recovered and redeployed on another site, or composted. The material does not degrade.
About the producer
Technical performance
EN 1946-3 · EN 12667 (thermal conductivity) · DIN 4102 (fire)
Life cycle
The granules are cork stoppers collected at more than 800 points across Belgium, then ground with no binder or additive. The bark comes from Mediterranean cork oaks.
De Vlaspit grinds the stoppers at Scherpenheuvel, in Belgium. On site, the granules are tipped dry onto a sheet and spread with a rake, or blown mechanically into cavities and roof spaces.
The granules can be taken out of a floor or roof and spread on another site. Failing that, they go to a fibre recycling stream or to industrial composting.
FAQ
Is the granule fill loadbearing?
No. It is spread loose, with no voids, in floors, ceilings, roofs or crawl spaces. Reaction to fire B-s1 d0 according to DIN 4102.
Which thickness should I choose?
Thermal resistance reaches 2.3 m²K/W at 10 cm and 3.5 m²K/W at 15 cm, for a conductivity of 0.047 W/m·K measured to EN 1946-3 and EN 12667. The granulate is supplied in 100-litre bags, ten bags to the cubic metre.
What happens to the granules at end of life?
They are recyclable and compostable. The cork used is itself already recycled from bottle corks.
Alongside
Same layer, same use · three materials to compare.
