The ancient Romans called oak "robur," and they used the same word figuratively to mean "strength." The wood of the oak tree is indeed strong, and it has other qualities as well. It has an attractive texture that appeals to furniture makers and a chemical composition that appeals to the wine industry.
The oak grows slowly and lives for a long time. This long, slow development gives oak wood great strength.
Oak wood has a greater density (i.e. mass per unit volume) than the wood of most trees. The density of the wood of the live oak (Quercus virginiana) almost equals the density of water.
Modulus of Rupture
The modulus of rupture shows how much weight you can put on a substance before it will break. The wood of the live oak surpasses most trees in the fracture test; only such woods as ironwood and hickory can support more weight without breaking.
Resistance to Decay
Oak wood is durable and resistant to decay. The oaken shrine of Edward the Confessor, an English king who died in 1066 A.D. is still well-preserved today.
Some types of oaks have tyloses, structures by which a tree insulates its plumbing system from water loss during dry spells. Tyloses make wood resistant to water. For this reason, oak wood was the building material of choice for the British navy until ironclads were invented.
Medullary rays are strands of tissue that extend from the centre of the tree all the way to the bark. The medullary rays of the oak give the wood a pleasing appearance, especially if the wood is quarter-sawn. To quartersaw, cut an oak log longitudinally into four equal sections. Then make boards by further longitudinal cuts parallel and perpendicular to the first two cuts that you have made.
Valuable Oak Species
The wood of the white oak (Quercus alba) is especially prized for its beauty. It is widely used for furniture and interior decoration. Red oak (Quercus rubra) is also attractive, but inferior to white oak. The English prize Quercus robur, called English oak or pedunculate oak.
The oak has open grain wood. This means that it has fairly large pores, which must be filled with a paste filler in order to give a fine finish to the surface of the wood.
Some oaks have sufficient elasticity to make good floors.
Lignin and Phenols
Oak wood is rich in chemical substances called lignins and phenols. These substances add to the flavour and aroma of wine enclosed in oak barrels during the ageing process.