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The Evolution of Cork

Cork has been an integral part of social and economic segments of many societies for over three thousand years. Use of cork has been documented as far back as 3000 B.C. where Chinese fishermen used cork as floats. Throughout history, production methods and finished goods related to cork have changed, yet the raw material and harvesting practices have remained virtually unchanged. In fact, the cork material used on the Space Shuttle as a heat shield bears the identical physical structure of cork used by the Romans and the ancient Egyptians.

Throughout the world the cork forests span an estimated 5.4 million acres, with the concentration being in the Mediterranean region. The most predominant countries for cork production are Portugal (33%), Spain (23%) and Algeria (21%). Other raw material producing countries include Tunisia, Italy and France. Small plantations of cork oak trees can be found in other places such as South America and Australia. The growth and establishment of the cork oak as a native tree in the Mediterranean region can be attributed to the particular climatic conditions as well as the natural habitat and relatively small number of natural predators. Beginning in the 18th century, cork became widely used in industry, particularly after the re-development of the cork stopper by Dom Perignon, a Benedictine monk well known for creating the first champagne.

Until the late 1800s the predominant uses of cork continued to be stoppers (wine and champagne) as well as flotation devices (fishing floats, etc.). At this time the cork industry saw significant changes in how cork was used and processed due to new uses that had been discovered for the raw material. One of the most important discoveries was insulation corkboard, a thermal insulation product made from 100% cork grain. This product was widely used for years as an insulating product in military vessels, railcars and for other general insulating purposes.

The Development of Cork Flooring

During the early l900s, cork became one of the most popular and widely used resilient flooring materials. From 1900 to 1945 cork was frequently used in government buildings, banks, universities and homes. In fact, one of the most renowned architects of that time, Frank Lloyd Wright chose cork for use in many of his residential designs including Fallingwater in Western Pennsylvania. Other installations during that period included The United States Department of Commerce Building, Department of the Interior Building and the National Archives, all located in Washington, DC (circa 1930). Institutional installations included St. Mary of the Lake Chapel, Mundelein, IL (circa 1920) and Lafayette College, Easton, PA (circa 1930). Despite high levels of traffic, all of these installations are still in use.

Cork flooring in the beginning of the 20th century consisted predominately of light, medium and dark shades. Additionally, wall base coving and stair nosing were a popular choice for commercial and residential installations. During this period, until the 1950s, cork tile manufacturing remained predominantly in the United States, Great Britain and Switzerland while Portugal and Spain processed and supplied the raw material. One of the most influential cork manufacturers, Armstrong, developed and manufactured a wide array of products in its Pittsburgh, PA and New Jersey facilities. Among these products was cork flooring, the first truly resilient flooring material. Later, due to changes in product taste as well as a major shift in cork manufacturing from the United States to Europe, Armstrong developed new products such as linoleum and vinyl which they are known for today.

Due to interest in different designs, lower prices and new products, cork lost much of the market share it had gained under the marketing focus of Armstrong and Kentile in the first half of the 20th Century. Again in the late l960s and early 1970s interest in cork increased but was nowhere near the levels of 1927 during which 2.9 million square feet of cork was sold. Only in the past 6 years has cork begun to re-establish itself as a viable floor covering alternative. The renewed interest has been a result of both environmental awareness as well as developments and changes in the product. As the interest continues to increase for durable, functional, environmentally sensitive floor coverings, cork will become a logical, integral part of the standard high end interior surface pallet.

Cork - From the Forest to Your Floor

Cork is the bark of the Cork Oak tree. The tree, grown predominately in Europe and North Africa, has a life span ranging from 150-200 years. Cork is harvested using traditional methods that have remain virtually unchanged since the uses of cork were first discovered. Once the tree has reached the correct level of maturity (typically 25 years), the first harvest of cork bark is removed from the tree. The cork is removed by first making an incision using a sharp knife into the bark. After this incision is made, the cork is gently removed from the tree in sections approximately 1’ X 3’. The cork is then carried to a centralized location in the forest where it is stacked and aged for a period of 3-6 months. This process is repeated every nine years henceforth, at no time affecting the health of the tree. Hand labor is used throughout the entire harvesting process to ensure that the trees are properly treated and protected. During each harvest, no more than 50% of the bark is removed, allowing the tree to protect itself using its natural defenses. Chemical pesticides and fertilizers are not normally used in the cork forest.

Like the production of the raw material, the manufacturing methods are also geared towards the protection of our environment. To produce cork flooring, virgin cork bark and cork waste from the manufacturing of other cork products is recycled and ground into small granules. The granules are baked in molds at varying temperatures, allowing shade variations, from light to dark, in the finished tile product. After being baked, cut into slabs, sanded and finished with our natural wax or polyurethane, the tiles are hand sorted to assure the highest quality final product. Any rejected material during production is recycled back into future products. Dyes and colorings are not used in the manufacture of Expanko’s solid Traditional Cork products and those used in Vallares Floating Floors are natural, water-based and fade resistant.

During the manufacturing process, all raw materials are consumed, either for the finished flooring product or as an energy source. Production waste consisting of cork dust and cork oak tree trimmings are burned in furnaces which supply the heat to bake the cork tiles. Not only does cork provide consumers with one of the most durable, beautiful and comfortable floors available, but it also helps conserve our precious natural resources. When installed, cork provides a long lasting floor, giving your interior a warm, natural look and feel that will retain its' functional beauty for decades.

Due to the cultural and financial significance that cork plays in many parts of the world, we are assured of a consistent supply. Additionally, the cork oak is resistant to attack from pests and other predators preventing any catastrophic loss of cork trees. The governments of those countries which control a significant percentage of the cork forests including Portugal and Spain have significant penalties for the removal or destruction of cork oak trees. Additionally, these governments subsidize re-forestation and preservation programs to encourage planting and maintaining the cork forest.

Expanko has maintained the highest level of quality by retaining many of the production practices used for the past 100 years. Expanko is the only company that offers such a wide selection of patterns and colors including our true light, medium and dark shade tile. Expanko sets the benchmark for cork flooring products by designing and manufacturing products to the highest standards using traditional methods of the past in conjunction with new advancements in production. Expanko remains committed to quality and retention of the historical properties of cork flooring and will continue to lead the industry in this direction.