Cork is fast becoming a sought-after ? if somewhat exclusive ? building material. Ben Watts ventures to the Portugal cork forests to find out more about the product
Sustainable, fashionable and flexible, cork is veering away from its age-old reputation as the material used primarily as a bottle stopper, to a versatile product that is today used in flooring, insulation and aesthetics.
The light, fire-retardant material, which is the bark of the cork oak tree, acts as an excellent thermal and acoustic insulator, and is impermeable to liquids and gases.
In Portugal, where a large percentage of the world’s cork comes from, cork forests have been protected by law since the 13th Century.
Cork oak wood was used for ship parts during the Age of Discoveries on Portuguese caravels, and was even used by the Ancient Greek and Roman civilisations as a noble and adaptable building material.
Despite the growing use of plastic and metal bottle tops in the bottle stopping industry, cork’s potential as a commonly-used material is growing, with demand coming from furniture manufacturers, insulation specialists and many construction niches.
Architects such as the Lisbon-based Barbini Arquitectos have been adopting the sustainable qualities of cork in recent eco-construction projects. The firm’s architect and co-founder Flavio Barbini describes the material as “versatile and distinct”.
“We have used the material on one project called the Ecocabana, an environmentally-friendly hut, which we want to use to educate people on the environment,” says Barbini. “Not only does cork act as an insulator, but it is a very versatile material to use.
“We have had to change our plans somewhat from the initial design stage, but as we learn more about the material we are becoming more likely to use it on other projects – especially projects in natural environments such as in forests and on beaches.”
Barbini notes that one of the benefits of using cork in construction is that it comes with a significant amount of heritage.
BUILDING AN ICON
“In Portugal cork is part of the culture, so as well as the environmental benefits, it is also an iconic material,” he remarks.
The bark of a cork oak is harvested on average every nine years, in a process that actually saves the tree from dying. Bark from a tree’s first two harvests, known as virgin and secondary bark, is usually used to make corkboard insulation and cork tiles.
The cork that is produced from the third and subsequent harvests, known in the industry as reproduction cork, is generally used for making natural and technical cork stoppers.
Other produce is used in granulated cork products such as floor tiles, memo boards, handles of fishing rods and gaskets. It can also be combined with rubber for gaskets, valves and insulation in buildings and railways, and has even been found in the nose cone of a space shuttle.
Architects, designers and decorators have been finding the material of more interest as a natural material in recent years and there now exists a range of decorative products in a variety of textures, tones and colours.
While it is more expensive than similar man-made materials, cork offers the construction industry a recyclable and biodegradable material that could help architects and builders meet the growing demand for ecofriendly buildings.