Wood Species: Cork

Scientific Name: Quercus suber.

Trade Name: Cork.

Family Name: Fagaceae.

Common Names: Cork, cork oak.

Regions of Distribution: Europe and North Africa.

Countries of Distribution: Spain and Portugal. Cultivated in Spain, Portugal, Tunisia, France, Italy, Morocco and Algeria as well as North America.

Appearance

Color: Varies from light to dark; many colors available depending on the manufacturer.

GRAIN: Distinctive look unlike wood—cork is the bark of a type of oak.

Variations within species and grades: Many patterns available depending on manufacturer.

Properties

Hardness/Janka: Varies.

Dimensional stability: Cork reacts quickly, sometimes within hours, to changes in moisture. Typical dimensional stability measurements do not apply to cork’s composite construction.

Origin: Southwestern Europe and northwestern Africa.

Availability: Readily Available.

Average and maximum lifespan: 150 to 250 years.


Workability

Sawing/Machining: Cork may be cut with a utility knife.

Sanding: Use the finest grit possible to flatten the floor. Use recommended sequence with a multi-disc sander or a hard plate on a buffer. If the edger is used, fine sandpaper. Small orbital sanders or hand-sanding are recommended for corners and wall lines, as hand-scrapers may gouge the cork.

Nailing: Cork is installed using adhesive.

Finishing: All surface-type finishes are successfully used on cork (choose a finish that will bend as the
cork compresses). Oil-and-wax also is used frequently.

Common Uses: This renewable, environmentally-friendly resources is used as bottle stoppers, barrel stoppers, flooring, low temperature insulation in coolers, refrigeration systems and storage warehouses; high temperature insulation for rockets, shoe insoles, roofing panels, dart boards, computer mouse pads, bulletin boards, fishing floats/buoys, fishing pole handles, building materials (bricks), to make the seams tight in woodwind instruments, baseball cores, soundproof tiles, cork paper for cigarette tips, gaskets and washers in engines and motors, keep pierced holes open, to assist in piercing, coasters, kitchen mats, under glass to keep it from moving, under potted plants to soak up excess water, earring backs, furniture, table tops, plug holes, cover flasks in laboratories, life preservers, tropical helmets, in linoleum, artificial limbs, badminton birds, pipe coverings, polishing, many craft projects, boats. Seeds have been used as a thickener in cooking and as a coffee substitute. Mulch is used as a pest repellent. Trees are used ornamentally.

Detailed Description

Plant habit and life style: Slow-growing, medium-sized evergreen oak with low dividing trunk, 20 m tall.
Stems: Moderate, light gray-brown, abundant gray fuzz. Bark is very unique, light gray with deep reddish brown furrows, developing very thick (inches) and insulating layers of cork, ruggedly ridged and furrowed; reddish brown when recently harvested for cork. Bark can be peeled off the tree every 10 years up after the age of 25 up to 12 times in its lifetime.

Buds: Buds clustered, reddish brown, with some gray fuzz, broadly triangular and pointed.

Leaves: Alternate, simple, evergreen, leathery, ovate to elliptical, 2 to 3 inches long, margin either entire or usually with wavy teeth; leaf surface cupped, dark green above, very fuzzy and whitened below.

Flowers: Monoecious; males are slender, yellow-green catkins 2 to 3 inches long; females are very small, in clusters of 2 to 4 in leaf axils; both appear in early spring.

Fruits: Acorn, 1 to 1 1/2 inches long, narrow, oblong; loose scaly cap covers approximately 1/2 of the nut; ripen the first year.

Habitat: Tree adapted to mild wet winters and hot dry summers. Medium to heavy, moist soils. Semi-shade to full sun. Cork is able to grow in a variety of places though it’s sensitive to cold. Provides habitat for a variety of wildlife species.  Considered a vital part of the ecosystem of which it is native.

Special Diagnostic Characters: The combination of leaf vestiture, form of the margin (entire, lobed, toothed, spinose), twig vestiture, and bud form and vestiture constitute the majority of diagnostic features minimally required at species level.