The only conclusion to be reached out of these facts is that perfect insulation is to incorporate two unique characteristics:
There is just a substance known to fulfil absolutely and truly those requirements. The material we are talking about is cork.
What is cork?
Cork is the cortex of the Mediterranean cork oak “Quercus suber”, growing in the south of Europe and the north of the African coast.
It is cultivated mainly in Portugal, Spain and Algeria.
Cork oak is a strong tree which can reach up to 20 or 25m high. Its cortex is suberized, that is to say, composed by cork, being relatively soft and spongy, very light-weighted and with deep cracks. Its cortex protects the tree from injuries, sicknesses and insects. It is a death tree part which protects the living one, most of all to survive drought (protecting internal tissues from water losses) and fires. When there is a fire, the internal cork side closes due to the heat and avoids oxygen entry and therefore combustion, protecting the tree internal parts, which enables it to regrow anew the next season.
Cork extraction is made by withdrawing cork oak cortex, where the material is located. Once cortex is withdrawn, the tree is “at rest”, and nine years later the extracting process will be renewed.
A very important part of cork industry is located in Spain (especially in Andalusia and in the south of Extremadura), where about 30 % of global production takes place.
Cork industry generates a sustainable economic activity, which does not pollute, and offers the global market a natural ecological product.