More than Meets the Eye
In this evolving world of man-made materials, it is important to recognize and celebrate those items that are still uniquely crafted from the gifts of the Earth. With the recent surge of environmental awareness, consumers and corporations alike have taken a preference for products that result in as minimal damage to the ecosystem as is possible. No industry has been granted exemption from adhering to the new trend of promoting Earth stewardship. For example, a young couple, also new homeowners, begins looking for something to replace the lime-green shag carpeting in the residence they just acquired, and finds themselves entering the world of sustainable flooring options. Here they encounter a surprisingly attractive cork. Most likely though, our unsuspecting consumers have no idea just how sustainable cork really is, because if they did, they would resurface the whole house at once - and their neighbors' floor too!
In examining this wondrous material, first take note that there is such a thing as a cork tree, which is in fact referred to as a cork oak tree. The most noteworthy feature of cork production is that the tree is not cut down in the harvesting process. One might then be wondering what in the world substantiates the final product. In actuality, what you see under your feet is manufactured from the dead cells of what is conventionally called the bark of the tree. This material is unique though, and for those who remember high school biology and cellular structure, the outermost dead cells on the cork oak tree do not form a tight uniform structure, but rather they form a loose and irregular latticework. This distinctive arrangement is responsible for the buoyancy of cork.
Although there is an abundance of oak (not cork oak) trees in America, the majority of cork hails from Portugal where the harvesting process is highly regulated and subsequently supervised by its government. This is big business for the country, and success relies on the health and maturity of these trees. For example, a cork oak tree will on average be harvestable for 150 years. This is an incredible gift from a tree that stands only 50 feet tall and 8 inches wide, on average. One of the main reasons it is so important to care for these trees in such a cautious manner is that the first harvesting of a cork oak tree cannot occur until the tree is around 20 years old – and the first harvest is at best minimally useful. On the other hand, the elder trees produce a significantly greater amount of the raw cork material, thus making them ever more valuable as time passes. For example, where a young tree can produce 30-40 pounds of material, a mature tree might produce upwards of 500 pounds.
As previously indicated, the harvesting of cork is a labor-intensive process, which requires stripping by hand the outermost layer of the bark. This is a skilled task, as the harvester must be careful not to damage the living tissue underneath the dead layer that is being trimmed from the tree. This trimming is achieved by using a hatchet that strips whole planks off the trunk of the tree, which are then left to dry in the hot sun. Given that the Mediterranean is home to a large portion of these cork oak trees, the drying step is well matched to the local weather conditions. The planks may be left out to dry for six weeks or for as long as a few months. As time passes on, the planks will lose between 18-22% of their original moisture, and in the meantime will become flatter. The next step of the process is necessary to ensure the cork is free from dirt and any other grime that accumulated during drying. At this stage, the cork planks are submerged in a chemical agent dissolved in boiling water for a time period of ½ hour to 1½ hours. As previously stated, cork's cellular structure allows it the ability to float on water, so during this step of the process, it must be weighted down in the boiling solution. Once this is complete, the next step is the additional trimming of any inferior portions of the planks. Normally this merely amounts to removing the top layer, which is a relatively minimal amount of raw material. At this point, the planks will undergo a second drying stage, only this time it will occur in a closed and controlled environment as opposed to outdoors. The remaining material is then pressed and cut into the desired shapes to be installed as flooring in homes around the world.
Cork is extremely cost effective, especially after considering that each tree is only harvested on a nine-year cycle. The increased notoriety of the product has boosted not only employment in the cork harvesting industry, but also highlighting the importance of maintaining a healthy forest for these ever giving cork oak trees.