Cork is the bark of Quercus suber. Its harvesting takes place every 9-10 years without ever felling the tree, making it a material with a deeply regenerative soul. In construction, it becomes the king of bio-compatible insulators.
For structural or insulating use, ground cork undergoes a thermal process in a steam autoclave (about 300 degrees C). This thermal shock causes the granules to expand and the suberin to melt, the natural wax of cork, which acts as the sole binder. The final product, Expanded Toasted Cork (ICB), is a dark-brown panel free of polyurethane or phenolic glues.
Unlike synthetic insulators, cork possesses a high specific thermal capacity that translates into excellent summer thermal lag (it delays the entry of solar heat by up to 12-14 hours). The biochemical composition of suberin makes it naturally rot-proof, water-repellent and impervious to rodents and wood-boring insects.
Standards
European and international references applicable.
Physical properties
Usage environment
Cork maintains its thermal lambda value even when wet — unlike mineral wools which collapse when soaked. It is the insulation of choice for basements, cellars and underground applications where incidental moisture contact is expected.