America's best kept secret
Published: 02 April, 2007
Red oak is ideal for flooring, doors, panelling and staircases and, says Michael Buckley of World Hardwoods, deserves to be more popular
There is much discussion as to why red oak is named as it is. Some say because the leaves turn red in the fall, rather than brown as in white oak. Others suggest that the wood has a reddish tinge, although that is often not the case. William A Lincoln, in his book World woods in colour, describes red oak as ranging from biscuit-coloured to pink. What is absolutely sure is that its name has nothing to do with red wine for only white oak is suitable for barrel making! However, American red oak is highly suitable for a whole range of applications from flooring to furniture, cabinets to coffins and every type of joinery from doors to decorative panels.
There have been many examples of fine projects in red oak in the past, not least of which is the organ casement in the church of St Martin in the Fields in Londons Trafalgar Square. Tim Rice used red oak for his Cornish staircase many years ago and even won an award, perhaps his only award for something that involved neither music nor cricket. But many of todays furniture makers and interior joinery manufacturers are unfamiliar with this oak, one of the most sustainable of all temperate hardwoods.
American red oak is a true Quercus, mainly Quercus rubra northern red oak and Quercus falcata southern red oak, but there are many others subspecies such as Spanish oak, cherrybark oak and shummard oak. They all exhibit much the same technical and working properties, but, as with most US hardwoods, can vary in colour and grain from region to region.
The percentage of heartwood in red oak is relatively large, particularly in northern grown material. Northern and southern is not differentiated by merchants, so, as usual when specifying American hardwoods, it is best to find out your source, if physical properties are more important than aesthetics. Most European hardwood importers and distributors are well versed in their different characteristics.
Red oak represents about 35% of the total American hardwood forest although the sawn timber imported into the UK does not reflect this, and hence the current promotion of red oak by the American Hardwood Export Council (AHEC). Nevertheless in 2006, the US exported almost 500,000m3 of which 4,297m3 or US$3.2m-worth was shipped to the UK.
Red oak is particularly easy to slice and peel for veneer and plywood and is very readily available from exporters and European markets such as Germany. As a result it is widely used for doors and panelling where its individual character offers decorative options for interiors to designers and architects. The tree grows large and tall, giving much better specifications than most other types of oak. The seed of the American red oak is resistant to fire and is often a pioneer species after fires, usually started by lightning, have destroyed others. In Pennsylvania after devastating natural fires in the early 1900s, it was red oak that came back to regenerate the forest naturally. The total growing stock of US hardwoods is estimated at 373 million m3 (source: USDA/FAS, 1992). Red oak has been cut continuously for widespread use since the European settlers first arrived and yet it increases its growing volume by sound management and natural regeneration always a true measure of sustainability.
The hardness of red oak makes it ideal for flooringLincoln describes American red oak as weighing around 770 kg/m3 with medium bending properties and very good bending with steam. It has high crushing strength and is mostly straight grained. Such properties led to AHEC in Europe to select red oak along with ash, white oak and tulipwood for structural testing by BRE several years ago. The results are contained in the publication, Structural Design in American Hardwoods which provides architects and engineers with structural data under Eurocodes not previously available. American red oak is classified as non-durable, although the sapwood is permeable and easily treated with preservative, whereas the heartwood is moderately easy to treat. This fact also enables American red oak to be more easily treated with fire retardant chemicals than some other hardwood species.
For example, using the heartwood treatability designations given in EN 350-2, American red oak is classed 2/3, easy to treat/difficult to treat, while European oak is more problematic being listed as Class 4, extremely difficult to treat. This better permeability of American red oak leads to a greater uptake and retention of chemicals necessary to achieve the Class 0 fire rating demanded by Building Regulations for internal linings used in escape routes and circulation areas in public buildings.
Other properties lead to the harder wood needing pre-boring for nails, but it machines well and also glues and stains well to a fine finish. The decorative properties of red oak are derived from its strong grain patterns and generally warm colour.
In performance the hardness of red oak makes it ideal for flooring, and with its distinct grain pattern it shows wear and tear less than many other species used today.
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