The composition of pine and spruce & grading
When a tree is ready for harvesting and felled, the trunk is usually debranched and cut into a butt log, a middle log and a top log.
Pine
The characteristics of Swedish pine vary across different parts of the log. There is also a distinct visual difference between the heartwood and the sapwood.
Spruce
Certain dimensions and qualities of Swedish spruce are also suitable for furniture production. Spruce has knots along the whole length of the trunk. The knots have a greater cross-section in the butt log and are smaller towards the top.
Common saw patterns – Block sawing
Quality grades of timber
The Swedish sawmills produce a wide selection of different qualities of sawn and planed pine and spruce. The Swedish sawmills can also provide specially ordered grades of timber, and timber with special dimensions.
Kiln drying
Nearly all sawn timber from Sweden is kiln dried: 50 percent is dried in compartment kilns and 50 percent in progressive kilns. Compartment kilns are becoming more common.
Compartment kiln
Progressive kiln
Target moisture content
Allowable variation for the average moisture content in line with EN 14298
Examples of target moisture content on delivery from manufacturer for different applications
When measuring the moisture content of all the pieces in a batch with a target moisture content of 16%, the average value for the moisture content of the whole batch (average moisture content) is allowed to fall between 13.5% and 18% to be approved. As regards the individual pieces in a batch, the moisture content of 93.5% of these must fall between 11.2% and 20.8%
Thicknesses and widths of timber
The tables below illustrate the dimensions of timber the Swedish sawmills normally produce for different areas of use - construction, building and joinery, and for other purposes. The cross-sectional dimensions are given in mm (thickness x width), and apply at a target moisture content of 18% for sawn timber and 16% for planed timber. Other dimensions are however also available, since the Swedish sawmills can adapt their production to both the national and international markets.
Cross-sectional dimensions of sawn timber
Cross-sectional dimensions common for planed timber
The handling and storage of timber
Timber should be handled properly in transit, in joinery factories and on building sites in order to achieve the best possible end results. Timber can be stored outdoors if it is protected from rain, snow, the sun, dirt and ground damp. Timber intended for visible indoor use, for example panelling, flooring, pre-manufactured joinery and fitments, should, when necessary, be stored in heated and ventilated indoor premises.
