Oak - England's Tree of the Year

The Wood Technology Society
,
29 Nov 2019

The Woodland Trust recently announced that England’s Tree of the Year, 2019, is an oak, situated in Calderstones Park, Allerton, Liverpool.  It is estimated that this oak is probably around 1000 years of age!  For more information click on this link, Woodland Trust

We have therefore gathered together a few interesting, and random facts about oak.

A 3,000 year old Bronze Age boat was discovered near Dover.  It was made from cleft oak boards about 3 feet wide.  The joints were sealed with a mastic made from moss and bees wax, and are still in place today.  For more information visit the Dover Museum website

The Latin name for oak, is “Quercus,” of which there are more than 200 separate species.  These are all true oaks.

The English oak (or common oak) is “Quercus robur.” Robur is Latin for ‘strength’, so the name fits the long use of oak in load-bearing applications in buildings.

The sessile oak (Quercus petraea) is also widespread in the UK, and the two hybridise readily. Their timber has very similar properties, and the leaves are both lobed. To tell them apart, Q. petraea leaves have longer stalks than Q. robur, but Q. robur has stalked acorn cups.

Oak has a durable heartwood, and is used for interior flooring/panelling, furniture, through to construction beams and joists.

Oak barn.

Oak, along with Scots pine, formed the backbone of medieval British society, from house building to building up the Navy into a war machine. Chaucer (1343-1400) termed oak “byldere oak” as it was the staple of all construction in Britain, and continued to be so until the industrial revolution led to greater availability of steel, brick and later concrete.

It is said that a Man of War (naval warship, 16th to 19th Century) required the wood of 3,000 mature oaks! A task made more complex by the need for certain naturally occurring crooked or bowed pieces, where the natural curved grain was selected to match the component. A single curved component had superior strength to the use of two jointed pieces to make up the shape.

Royal Navy Men of War

Our success on the open wave is attributed to the ‘wooden walls’ of Nelson’s navy, and the song “Heart of Oak” became the marching song of the Royal Navy (as well as the Canadian, New Zealand and Australian Navies). The heart being a reference to the durable heartwood of the tree.

 “Royal Oak” is a very popular name for pubs!  And oak is the preferred timber of cooperage (barrel making). The flavour of Scotch whisky is derived from the complex mix of tannins, lactones and other phenolic compounds in the oak wood. More recently American white oak has increasingly been used (never red oak – it is too leaky!) for casks.

English oak is quite different from its American cousins, red and white oak, both of which are more readily commercially available in the UK.

A misconception is that English oaks produce one of the hardest timbers on the planet.  Beech, hornbeam, rowan, field maple, wild cherry, silver birch, ash, box, apple and pear are harder.

Another misconception is that oak is the best timber for outdoor joinery.  Unfortunately, this is not the case.  It splits and weathers very badly if not constantly well maintained. Although the high natural durability of the heartwood means it will last a long time in exterior applications, where this rustic appearance is acceptable.

Oak is commonly used for coffins (although these days many are MDF with an oak veneer).

Oak is acidic and can therefore corrode certain metals, especially iron.

The ornamental oaks often found in parkland are generally Quercus ilex, or holm oak, noted for their evergreen appearance. They were introduced to the UK in the 16th Century from the Mediterranean.  Their leaves are more toothed than lobed, but it still bears distinctive acorns.

Nevertheless, oak is a national treasure, as celebrated by John Evelyn in his book Sylva (1664)

As long as the lion holds his place as king of beasts,
And the Eagle as king of birds,
The sovereignty of British trees must remain to the oak