Many people think of cork, if they consider it at all, as a relatively new and possibly unproven surface flooring option. Yet, there are examples of cork floors in public buildings, such as the Library of Congress, that were installed more than 100 years ago and are still in use today.
A proud history
A member of the beech family, the cork oak tree grows in coastal regions of the Mediterranean. Relatively slow growing, these trees survive harsh conditions in depleted soil that supports little else of value. Some cork oaks live to be 400 to 500 years old, though the average life expectancy is 100 to 120 years.
Unlike most trees, whose primary value is derived from lumber, cork is obtained from the bark of the tree. This unusually thick bark is made up of millions of tiny prism-shaped air pockets that produce a resilient cushiony surface and lead to the assertion that, with a cork floor, you are literally "walking on air." Cork is grown on farms and harvested every nine to 11 years. Rather than felling these trees, cork farmers try to keep them alive and producing for generations.
Cork has a long and distinguished history as an agricultural product. In ancient times, it was used for sandal soles, food storage vessels and floats for fishing nets. The seventeenth century French monk, Dom Perignon, is credited with being the first to recognize its suitability for containing sparkling wines, establishing the cork bottle-stopper industry. Over time, cork became more important as a cash crop, resulting in governmental regulation offering protection and placing restriction on ownership, production and harvesting.
Figure 1. Consumer demand drives cork flooring into many non-traditional applications.
The flooring option
The ability to use cork in flooring applications wasn't discovered until the 19th century, when an American, John Smith, discovered agglomerated cork. Today, cork flooring is produced from the post-industrial byproduct of the bottle-stopper industry. This "waste" material is ground up and reformed into sheets, using minimal amounts of adhesive to bind the particles together under high pressure. The size, quantity and type of cork granule, in conjunction with varying degrees of pressure, make the difference between "bulletin board" material and a surface suitable for flooring applications.
Historically, cork floors were finished just as any other wood floora paste wax was buffed into the surface. However, this labor-intensive maintenance was viewed as a real drawback when rolled sheet vinyl and similar "modern" resilient surface options came on the market in the middle of the past century. Cork flooring fell out of favor and, for perhaps 30 years, was not readily available to the general public.
During the past decade, new finishing techniques and improved technologies have revived interest in cork flooring. Though still a small fraction of the overall floor covering market, cork is enjoying a surge in popularity, driven in large part by consumer demand (see Figure 1).
What does cork have to offer that sets it apart from other surface flooring materials? Quite a bit, it turns out. In fact, no other floor covering can match the combined benefits of cork.
Carpet: When it comes to soft surface flooring, carpet is the obvious choice, but it has drawbacks, particularly in an industrial environment. Carpet fibers absorb liquid and conceal grit and microorganisms, making carpet difficult, if not impossible, to clean. While cork may not be a soft surface, it's a resilient one that provides many of the same benefits associated with carpet. Cork is warm, quiet and gentle underfoot. Furthermore, the inherent anti-microbial characteristic of cork makes it a natural in applications where health and hygiene are matters of concern.
Ceramic tile or concrete: No commercial/industrial flooring surface can match the virtually indestructible and solid, reliable, easy to maintain characteristics of ceramic tile and concrete. On the other hand, these materials definitely have their negatives. These hard surfaces are loud and produce echoes. They are unforgiving to both objects and people, causing damage to dropped materials and fatigue when workers must stand on them for any period of time. In contrast, cork provides a cushioned surface that places low stress on joints, feet and back. Cork's use as sound insulation is testimony to its value in a commercial or office environment.
Hardwood: Considered an all-around, good general purpose flooring material, hardwood is a repairable classic that won't go out of style. Wood is readily available in a variety of widths, installation options and designs. Many of these same benefits carry over to "the other wood flooring," cork. Cork can be finished and re-finished in the same manner and using the same products as those applied to any other wood. Unfinished cork can be stained, bleached, pickled, painted, etched, inlayed or installed with a border or in a parquet pattern. Truly, the possibilities are endless.
On the down side, wood that is either waxed or finished with polyurethane can be difficult to maintain to its "just installed" beauty in a shop environment. Often an annual re-application of polyurethane will require at least 48 hours of down time, while wax maintenance entails on-going intensive upkeep. In addition, wood flooring can become distorted when exposed to moisture continuously. These realities apply to cork as well.
A standout advantage is that cork doesn't spread flame and is, in fact, rated as a fire inhibitor.