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The story of the Natural Cork® floor begins in Portugal...
THE NATURAL CORK TREE
A member of the beech family, Quercus Suber or the cork oak tree grows in coastal regions of the Mediterranean.
Seven countries comprise the bulk of the area where cork oak will grow. These countries are Portugal, Spain, France,
Italy, Algeria, Morocco, and Tunisia with the majority of the production occurring in Portugal and Spain. Relatively slow
growing, cork trees survive harsh conditions in depleted soil that will often support little else of value. There are
examples of cork oak trees that are 400 to 500 years old, though the average life expectancy would be 120 to 200
years.
Unlike most trees where primary value is derived from the lumber of the trunk, Natural cork is actually obtained from
the bark of the tree. This unusually thick bark is made up of millions of tiny prism-shaped air pockets, which create a
resilient cushiony surface that offers several distinct advantages to the tree. Natural cork is a natural fire inhibitor so
the bark provides protection from wildfires common to the region. An inherent waxy substance, Suberin, serves as an
insect repellant eliminating threat from many usual agricultural pests. In addition, the bark is regenerative, so its
protective properties will grow back if damaged in any way.
A PROUD HISTORY
Natural cork has a long and distinguished history as an agricultural product. In ancient times, cork bark was used to
form sandal soles, food storage vessels, and floats for fishing nets. There are mentions of cork and its uses in many
ancient documents and literature surviving from as far back as 400 BC.
Seventeenth century French monk, Dom Perignon, is credited with being the first to recognize the ability of cork to
contain sparkling wines. This discovery is responsible for establishing development of cork bottle-stopper production
into the important industry it is today. Over time, cork became more and more important as a cash crop resulting in
governmental regulation offering protection and placing restriction on ownership, production, and harvesting.
Cork Harvest Regions
Rulers in Portugal were quick to recognize the economic value of cork
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and took early steps to secure its benefit for themselves. By the 14
century, ownership, growth, harvest, and sale of cork were closely
regulated, even to the point of dictating how windfall branches could be
disposed of. Many of these restrictions are still in place and can surely
be credited with the strength of Portuguese cork production in the
world economy. Portugal is the leader in corkwood farming at more
than 50% of production and is responsible for many of the
internationally adopted protective measures governing the growth and
manufacture of Natural Cork®. In Algeria and Tunisia, cork trees were
not offered similar protection, which resulted in almost complete
deforestation by the turn of the last century. An effort to replant the
region has experienced some success.
Natural cork is enjoying resurgence in popularity today. From television design shows to shelter magazines, natural
cork is seemingly everywhere and ostensibly the “hottest new product” on the market. Many people think of cork as a
relatively new and possibly unreliable option particularly as a surface flooring material.
“From 1900 to 1945 cork was frequently used in government buildings, banks, universities and homes. Frank Lloyd
Wright, one of the most renowned architects of that time, chose cork for use in many of his residential designs
including "The House on a Waterfall" in Laurel Highlands, PA. Other installations of that period, which are still in use
today, include the Department of the Interior Building and the National Archives (circa 1930), in Washington, DC, St.
Mary of the Lake Chapel, Mundelein, IL (circa 1920), and Lafayette College, Easton, PA (circa 1930).
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As product, tastes changed and cork manufacturing shifted from the United States to Europe… (Manufacturers)
developed new products such as linoleum and vinyl, which they are known for today. Consequently, cork lost much of
the market share it had gained in the first half of the 20th century. In the late l960s and early 1970s, interest in cork
again increased but fell well short of the levels of 1927 when 2.9 million square feet of cork were sold.” Cork History
…Google Books
NATURAL CORK AGRICULTURE
Grown on farms and harvested every 9 to 11 years, the financial benefit lies not in felling these trees but in keeping
them alive and in production for generations.
Regulations necessitate that a cork tree may not be harvested until it is 20 to 25
years old. The material from this first harvest is known as "virgin" cork. Virgin
bark is less desirable as it is tough and irregularly formed. The next harvest
results in product that is called "secondary cork" which, though of better quality
than virgin bark, is still not ideal. After extracting these first two layers of cork,
subsequent harvests produce "amadia.” With the harvest of amadia, a cork oak
tree has reached its optimum production value. At maturity, a typical tree can
produce upwards of 450 pounds of cork per harvest. This takes right around 50
years to achieve. Starting a cork tree farm is an investment in future
generations.
Often cork farms are combined with other
forms of agriculture such as raising pigs or
growing another crop in and among the trees. These combinations work well for
local farmers to balance the protracted production cycle of cork farming.
Natural cork is still harvested by hand in the traditional method leaving the
habitat intact and with minimal impact on the overall environment. Removal of
the bark, known as “stripping,” must be done during the active growing season,
June through August. Using hand tools, a series of cuts are made in the bark, one
at ground level, one just below the first branches, and two vertical cuts joining
these. The loosened bark is then pried off in two large sheets where possible and smaller bits if not. Sheets of cork are
stacked and left for days to dry in the sun, before being sent to factory.
GREEN BUILDING WITH NATURAL CORK®
With increased national and international attention placed on the environment and our natural resources, the trend
toward taking care of our environment through independent and collective action has since developed into what is
now known as the “Green” business ethic. Today’s average consumer is interested in healthy living and looks for
products that support this ideal. Natural Cork® is one of those products.
Natural Cork® is environmentally correct as well as improving health and comfort for human indoor living. In our
homes, Natural Cork® floors create a warm, comfortable, resilient surface that is gentle underfoot, is anti-microbial,
will not spread flame, and is inherently resistant to molds, mildews, and common pests. From harvest to production to
installation, cork is environmentally sustainable, non-toxic, and healthy.
Natural Cork® floors contribute to satisfying LEED credits for Rapidly Renewable Resources, Recycled Content, and Low
Emitting Materials under the LEED Rating System. The LEED (Leadership in Energy and Environmental Design) Green
Building Rating System is the nationally accepted benchmark for the design, construction, and operation of high
performance green buildings as administered by U.S. Green Building Council. USFloors is a member of the USGBC.
The determining factor for indoor air quality is the quantity of noxious emanations from volatile organic compounds in
adhesives and finishes. Natural Cork® floors are produced with adhesives and finishes from European manufacturers,
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A Div. of USFLOORS INC. | 3580 Corporate Dr. 30721
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which use no added urea formaldehyde or caustic chemicals in binding the cork granules. Natural Cork® core board
material that provides the structure for the cork veneer is also formaldehyde-free.
Natural Cork® begins in the orchards of Mediterranean Portugal with a sustainable harvest. Using techniques and tools
that have been passed from generation to generation, the bark of the cork tree is gently peeled away by hand. Once
harvested, the cork bark is left in the orchard for several days until it is cured and ready to be used for production. The
tree is not harmed or felled and this most sustainable of materials can be harvested every 9-10 years for 200 years or
more.
The cork bark is first used for bottle stoppers, and the left over material is graded, with premium grades being used for
beautiful, durable, and comfortable Natural Cork® floors.
Cork is one of nature’s most environmentally friendly products. Cork trees capture carbon dioxide (CO2) from the
atmosphere to help against global warming and provide socio-economic benefits to vast areas in the Mediterranean
region.
Natural Cork® floors provide you with an environmentally responsible flooring option that provides warmth and natural
beauty to your home.
Features & Benefits
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A Natural Cork® floor combines the warmth and comfort of soft surface floors with the durability and ease of
maintenance of a hard surface floor.
Comfort
Cork is made up of millions of tiny air pockets, which provide a cushion of air to walk on. This provides
exceptional resilience and reduces impact stress to the back and feet. A Natural Cork® floor is an excellent
choice for areas where prolonged standing occurs.
Warm and Quiet
The cellular structure of cork provides additional thermal insulation and makes it warm to walk on. This is
especially noticeable on cold winter mornings. The unique cell structure also acts as a sound absorber to keep
noise down and help keep your surroundings peaceful.
Durable and Easy to Maintain
Natural Cork® floors are finished with our Endura AR+™ high performance finish with advanced generation
abrasion resistance ensuring many years of enduring beauty. Natural Cork® floors are easy to maintain and do
not require any more maintenance than a traditional hardwood floor.
Healthier Indoor Air
Natural Cork® floors are certified by the GREENGUARD Environmental Institute to be a product that does not
introduce unhealthy fumes in the workplace, ensuring better indoor air quality. BASF’s Acrodur binders
eliminate formaldehyde and other harmful products from manufacturing. You can breathe easier with Natural
Cork® floors.
Naturally Mold and Fire Resistant
Cork naturally produces a chemical called Suberin to protect it from insect infestations and forest fires.
Suberin remains in the floor and provides natural resistance to mold, mildew, and micro- pests and insects. It
will also resist flames.
Easy to Install
Natural Cork® floors are easy to install either using the USFloors Propack for gluing or the glueless patented
CorkLoc® tongue and groove installation system. No need to stay off the floor once it is installed. Your Natural
Cork® floor can be walked on and enjoyed immediately after installation.
Lifetime Warranty
USFContract backs your Natural Cork® floor with a commercial Wear Warranty, a Lifetime Structure Warranty:
see product technical sheet for more information.
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A Div. of USFLOORS INC. | 3580 Corporate Dr. 30721
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COMPARISON CHART
Natural Cork floors combine the best characteristics of hard surface and soft surface flooring.
NO OTHER FLOORING OPTION COMPARES! See for yourself:
Easy to Clean
Durable
Resilient
Scratch Resistant
Acoustic Insulator
Warm/Thermal Insulator
Comfort Underfoot
Mold/Mildew Resistant
Resists Insects
Fire Inhibitor
Easy to Install
Easy to Repair
Increases Property Value
All Natural
Natural Cork®
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Vinyl/VCT
Yes
Yes
Yes
No
No
No
No
No
Yes
No
No
No
No
No
Ceramic Tile
Yes
Yes
No
No
No
No
No
No
Yes
No
No
Yes
Yes
No
Hardwood
Yes
Yes
No
No
No
No
No
No
No
No
No
No
Yes
Yes
Laminate
Yes
Yes
No
Yes
No
No
No
No
No
No
Yes
No
No
No
Carpet
No
No
No
NA
Yes
Yes
Yes
No
No
No
No
No
No
No
THE FLOORING OPTION
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The ability to use cork in flooring applications was not discovered until the 19 century when American, John Smith,
discovered agglomerated cork. Today, cork flooring is created from the post-industrial by-product of the bottlestopper industry. This ‘waste’ material is ground up and then formed 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 material suitable for flooring
applications.
Historically, cork floors were finished in the same manner as any other wood flooring, i.e. with a paste wax buffed into
the surface. However, the labor-intensive nature of this maintenance routine was seen as a real drawback when rolled
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sheet vinyl and similar ‘modern’ resilient surface options came on the market in the mid-20 century. New factory
finishing techniques and improved technologies have revived interest in cork over the past decade
What does cork have to offer that sets it apart from other flooring choices? Quite a bit, it turns out. In fact, no other
floor covering can match the combined benefits of cork.
PRODUCT OPTIONS
The basis for Natural Cork flooring is agglomerated sheet material produced mainly in Portugal and Spain. There are
two types of wear layer construction:
 Homogeneous: Tiles are compressed granules, traditionally offered in three shades light, medium, and dark.
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Veneer: In order to achieve a different appearance, it is necessary to laminate a thin veneer layer of cork on
top of this core material. Lamination takes place at the time of original production making the thin layer
inseparable from the core. The veneer layer carries the pattern. There are many patterns to choose from,
everything from those that favor wood to those that mimic marble, and much in-between.
NATURAL CORK®homogeneous and veneers – Glue-down tile, often referred to as parquet, and are generally available
in a range of patterns and colors, finished or unfinished, 12” x 12” or 12” x 24” are standard. It is possible to special
order in other sizes up to 36” x 36”, which is the limit of the production machinery. Tiles can be installed over wood or
concrete substrates that meet the qualifications for sheet vinyl applications. The preferred method of adhesion is
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A Div. of USFLOORS INC. | 3580 Corporate Dr. 30721
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water-based contact cement. It is not recommended to install tile in below grade situations, primarily to avoid
adhesion failure.
Homogeneous
Lineal Veneer
Geometric Veneer
Organic Veneer
NATURAL CORK PLANK – When applied to cork, the term ‘plank’ refers to a floating floor
installation, where cork has been laminated to a fiberboard center core [HDF] with a tongue &
groove edge. This allows for several advantages:
 Subfloor preparation is less stringent
 The floor ‘floats’ and is less visibly affected by expansion and contraction normal to wood
products
 Plank can be installed below grade
 Installation is relatively quick
 Thicker product provides better insulation
As is common with other floating products, Natural Cork plank requires a perimeter expansion space that must be
covered by baseboard or other trim. The necessity for perimeter expansion makes it difficult to use plank in a place
where it will not be convenient to install trim pieces.
Natural Cork® plank products are milled with a specially shaped “click” together tongue & groove center core. This
sophisticated and highly accurate milled shape ensures a very tight connection during installation and beyond. Click
technology is a glueless installation resulting in less mess, less fuss and less time on the job. What’s more, flooring that
is clicked into place and is unclicked for easy repair or re-use in another installation area.
UNDERLAYMENT – Cork underlayment is used specifically for its ability to provide acoustic insulation. Available in both
rolls and sheets, underlayment is used beneath other surface flooring to decrease noise transmission of reverberation
and impact sound. With ceramic tile, cork underlayment can also reduce stress-related cracking.
WHAT TO LOOK FOR:
DENSITY – Product density translates to product durability with a higher density meaning a stronger product.
Measured in pounds per cubic foot, Natural Cork® flooring has a minimum density of 28 lb/sf though densities of up to
34 lb/ft.
FINISH – Natural Cork® can be purchased unfinished but, unlike some wood, it must be finished upon installation.
Though some commercial facility management administrators prefer paste wax, the most common finish today is UV
acrylic. A new introduction of cork with a vinyl coating that is denser and stain resistant has been introduced for use in
areas where heavy roller or pivoting traffic occurs the latest development in finishes is targeted on “anti-scratch,” a
more durable coating. Cleaning and maintenance products are available from USFContract/USFloors.
THICKNESS – The thickness of the Natural Cork® wear layer has less to do with durability than will density. However, it
will be a source of improved insulation both acoustic and thermal. A good standard thickness is 3/16” (4 mm). Again,
other thicknesses are readily available and particular needs can be met through special order.
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MAINTENANCE
With Natural Cork®, lasting beauty can be achieved through purchasing a top quality material and providing proper ongoing maintenance.
Providing proper maintenance begins with remembering two key properties of cork, its ability to fade with exposure to
light and the fact that it will react to heat and humidity.
Natural Cork® contains organic pigments. Just as in other wood products, Natural Cork® will fade over time. Natural
Cork® products should never be exposed directly to sunlight. Use drapes or other systems to protect your floor from
excessive light will slow down this process. Cork will naturally yellow or mellow with age. Uneven exposure to light
sources will cause uneven ageing so it is a good idea to rotate furnishings periodically.
All wood floor systems expand and contract in response to fluctuations in temperature and humidity. By controlling
the environment, maintaining a moderate temperature and relative humidity around 50%, one can minimize the visible
effects of the normal contraction and expansion of your floor.
It is important to sweep or vacuum the floor regularly in order to avoid buildup of abrasive particles that can scratch
the finish. Most cleaners specified for use on pre-finished hardwood will also work with Natural Cork® products, but be
sure to read packaging for correct information. These cleaners should be sprayed or misted over the surface and
damp-mopped up as you go. It is not a good idea to use the old “bucket and mop” cleaning method on a Natural Cork
floor. Spills should be wiped up immediately.
Weight distribution is a key factor in preventing indentation. To minimize impressions in the resilient cork, furniture
should have proper protectors under feet and furniture with casters should have wide casters. Cork has the resiliency,
when indented it will regain its original state nearly 100 percent over a short period. Protective mats are a good idea
under office chairs.
REFINISHING OPTIONS
Most Natural Cork® decorative patterns are made of thin veneer laminated to a cork base. Failure to maintain the
finish could result in irreparable damage to this pattern layer. The longevity of the finish can be directly related to
traffic intensity and quality of floor care. When a Natural Cork floor starts to show a traffic pattern and signs of wear, it
is time to renew the finish.
All Natural Cork® finished products are compatible with Bona Kemi maintenance and refinishing products for wood
flooring. Consult the maintenance information of each product to review specific products.
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