Trade Name: Terms such as ‘figured’ may be applied to describe unusual appearance characteristics. The name Burr Elm or Elm Burl is applied to wood that has a very convoluted grain structure which in the cut wood shows as whorls, curls, twists and birds eye features. Elm Burr-wood most often comes from growths that can develop around the base of the tree.
Origin: European species occur predominantly in England, Wales and the near continent, though Wych Elm is found in Northern Europe and Scotland.
Appearance: The appearance of White Elm and Slippery Elm is very similar to the European species. The sapwood is wide and pale brown while the heartwood is darker and is sometimes slightly red. The growth rings are distinct and create a pleasing figure, which is enhanced by some cross grain. Grain can be straight but is often interlocked. This combination of features results in dissimilarity of grain appearance from log to log. In Rock Elm there is less distinction between sapwood and heartwood and the growth rings are less striking. The colour is pale brown, grain is generally straight and texture is finer than other Elm timber.
Mechanical: White Elm is fairly light in weight with a density of 560 kg/m³. It is tougher and stronger than European Elm. Rock Elm is heavier with density up to 750 kg/m³ and is extremely tough. Neither is regarded as durable. The girth of White Elm can reach over 1m. Rock Elm is smaller with girth up to 600mm.
Availability: White Elm and Slippery Elm are sold together as one variety. Veneer is available usually crown cut. Burr-wood veneer is available from specialist suppliers.
Timber Cuts: Elm is prone to interlocking grain that can be troublesome during machining operations. Elm in the solid generally matches well in colour to the veneer form, though it should be understood that veneers are taken from logs selected for absence of contentious features. It may not be commercially practicable to avoid such features in the solid material. Many features and marks are not exposed prior to the moulding operation and cannot be selected out. The wood is regarded as stable once properly dried.
Veneer Cuts: Elm veneer is produced from selected logs in which unwanted characteristics are limited or not present. The logs are most often sliced to produce crown veneer. White Elm veneer (and the European) is of striking appearance, usually with a strong figure and some quartered grain at the edge of the sheet. When laid up the overall appearance is usually stripy. Rock Elm displays a much milder and more finely grained appearance. As each log has individual character, it is well to view the range of material needed in order to plan any requirement for matching. The best Burr Elm veneer displays tight and continuous burrs and is particularly effective when quarter matched as a feature panel with an inlaid surround. Supply of well-matched material needs to be planned for.
Relative Costs: Crown veneer 3. Burr-wood veneer 10
Properties: The solid material machines well, though care is required in view of the probability that some interlocked grain structure will be encountered. The wood is somewhat coarse (less so in Rock Elm) but a good finish can be produced. Both solid wood and veneer take stain and polishes.
Seasoning: White Elm is said to season more easily and with less distortion than Rock Elm or the European species.