Solid wood and wood products

Solid wood

Once the branches and bark have been removed, entire tree trunks can be used as 'roundwood', but in most cases, the trunk is sawn into boards or battens with a rectangular profile. The trunks can be either 'cross-sawn' or'rift sawn'. In the latter method, all saw-cuts are parallel, whereby the faces of the resultant planks each have a different angle to the tree's growth rings. In quarter-sawn wood, the rings are all relatively perpendicular to the face of the board (Figure 8.8). Although more expensive to produce, quarter-sawn lumber tends to be more dimensionally stable, while rift-sawn wood is more likely to distort in the ways illustrated previously. Rift-sawn wood shows the typical 'flame' grain which is so appropriate to decorative applications (Figure 8.9). After sawing, the boards are squared (the sides sawn off to produce a straight edge), and sawn again into beams or planks (usually) of standard dimensions.Those standard dimensions differ from country to country. The Northern European lumber sizes are generally applied to spruce and pine, while other woods are subject to the grading rules of the countries of use. In the Netherlands, the Dutch NEN standards apply to much of the timber supplied, although some is subject to the sizing used in other countries, such as the Nordic Timber Grading Rules.


Was this article helpful?

0 0

Post a comment