By Emily Hooper
There is one word that explains a space shuttle component, a county in Southern Ireland, an expression that rudely tells someone to be quiet and green floor covering— cork. A word recognized by various meanings for at least 2,000 years, the mainstream flooring industry fell in step at the turn of the 20th century, laying cork mainly in commercial applications with a small footprint in homes.

The recent growing awareness of manufacturing and production effects on the environment has once again brought cork into the limelight, this time for its environmental attributes, though its inherent durability and sound deadening properties remain unchanged. With its effects from growth to the home, cork has proven itself a green element that makes a goal of sustainability attainable.

The material used in cork flooring comes from the bark of the quercus suber, a variety of oak grown in the Mediterranean region, about 50% of which comes from Portugal. It is one of the few types of wood flooring that doesn’t sacrifice the life of the tree to harvest material. Instead, after nine years of maturation, the bark of the tree is stripped using hand-harvesting techniques, keeping the tree alive, similar to the way in which a sheep is shorn.

“Regular extraction of cork is a fundamental contribution to the environmental, economic and social sustainability of the rural areas of the Mediterranean where the cork oak thrives,” said Ronit McGuthrie, marketing manager of Amorim.

Cork removes more CO2 from the atmosphere than traditional wood flooring species because the resource is harvested without felling the tree, said Gary Keeble, marketing manager of USFloors.

Beyond keeping the tree alive, removing the bark actually improves carbon dioxide absorption. “The repeated stripping and regeneration of cork bark absorbs three to five times more CO2 than a non-harvested tree,” explained Ann Wicander, president of WeCork.

Socio-economic benefits are an added bonus of traditional harvesting. As a trade that has been virtually unchanged for two millennia, it employs over 40,000 strippers and producers, she continued.

Waxing environmental

Growth of the tree requires little to no pesticides, as cork naturally protects itself by producing a waxy substance known as suberin, named after the tree’s scientific name. In addition to blocking pesky insects, suberin naturally regulates the water and nutrient intake of the plant.

“Suberin is highly hydrophobic and its main function is to prevent water from penetrating the tissue,” explained Randy Gillespie, owner and director of sales and marketing for Expanko. “It moderates the substances that pass into the organism, acting as a barrier to harmful substances and microorganisms while facilitating the intake and storage of water and other nutrients.”

He continued that these inherent features reduce the need for pesticides, which can be transferred to the tree and washed into the soil.

The substance works wonders in the home as well, once the cork bark has been transformed to a floor. All the properties present in the orchard transfer to the final product, making cork one of the smartest flooring options. As a closed cell protected by suberin, the flooring is naturally resistant to mold and mildew.

“On our Natural Cork floating floors we attach a cork underlayment to the back of the HDF board for two benefits,” explained Keeble. “The first is for the sound reduction properties and the second is the antimicrobial benefit of the suberin, as the void between the subfloor and the floating floor panel is the most likely place for mold or mildew to grow.”

Prevention of mold growth certainly contributes to indoor air quality (IAQ) within a home and manufacturers have gone one step further to also ensure that the production of the flooring product is as green as the cork itself.

“USFloors uses BASF’s Acrodur water based binders instead of traditional resins used to manufacture cork flooring, eliminating harmful ingredients such as phenol, formaldehyde and isocyanates,” said Keeble.

Amorim also uses Acrodur technology and touts its technical performance, according to McGuthrie.

Cork helps out with energy usage and costs, too. One cubic inch contains 200 million 14-sided, closed air cells, that naturally insulate and absorb sound, said Wicander. “An R factor of 2.6 gives great thermal insulation, keeping the floor cool in the summer and warm in the winter.” End users have the feel of—and actually are, to some extent—walking on air.

The end of a cork floor’s life also has an eco spin. The product’s life cycle is one of the longest of any flooring option—the National Library of Congress’ cork floors have been in use for over 100 years. However, when it comes time to replace them, cork is recyclable and biodegradable, although there is currently no organized recycling program, noted Wicander.

“Cork can be reground and used again in underlayment or other cork products,” said Gillespie. “If it does end up in a landfill, it will biodegrade just like a piece of wood with no negative effects.”