Sawn Timber
Sawn timber is a collective name for wood products made by cutting conifer and broadleaved logs. Hereat, a product must have only one cutting face. Rough timber, so called “ordinary” sawn timber is divided into panel timber (boards, planks and slabs); squared timber (scantlings and beams); rough-edged timber (prisms and beams) and small fry timber (laths and batens). Following the origin we distinquish the conifer (spruce, fir, pine, larch); the broadleaved (beech, oak, ash, maple, elm, harnbeam, birch, linden, alder, poplar) and other sawn timber (e.g. aspen).
Edged sawn timber has parallel areas and edges perpendicular to them. Edges can be parallel or tapering. Unedged sawn timber has parallel areas and unedged sides or sides partly edged but with bigger wanes than it is allowed at the edged timber. A facing area is of higher quality than a backside area. An external or left area is turned-up to the sap. An internal or a right area is turned-up to the pith. We always count the shortest distance between areas, sides or faces of sawn timber in the specified measure point when measuring the diameter, width and length . The dimensions mentioned above are those coressponding to the moisture of 20 – 22% abs. with accuracy in the range of permitted deviations. Division of sawn timber by shapes depends on particular dimensions that are strictly done.
Sawn timber has been the oldest wood product for centuries. The manufacture is quite simple and the volume of production constantly rises both in The Czech Republic and the surrounding European countries. Sawn timber is made of different existing tree species. Here in our country it is mainly conifer and broadleaved trees.
By dimensions we divide sawn timber to boards, planks, scantlings, beams, batens, laths, battens and both small and big sleepers.
Dimension timber is sawn timber with demensions corresponding to its final application. Unsurfaced sawn timber is rough and undressed and surfaced timber for final application is surface dressed.
Sawn Timber Divided By Shapes And Cross-Section Dimensions
Panel
The minimal width is double of the diameter.
- boards (maximal diameter is 40 mm)
- planks (diameter is more than 40 mm)
- slab boards (maximal diameter is 25 mm and the left face must be leastwise touched by saw along all the length)
- slabs (maximal diameter is 25 mm)
Squared
Cross-cut, it ususally has a right angle and the width must be less than double of the diameter.
- balks (cross-cut has more than 100 cm2)
- scatlings (cross-cut has 25 – 100 cm2)
- laths (cross-cut has 10 – 25 cm2)
- battens (cross-cut has less than 10 cm2)
Rough-Edged
It has parallel areas and edges are round.
- beams (diameter is more than 100 mm)
- prisms (maximal diameter is 100 mm)
Sawn Timber Divided By Processing Techniques
- edged (edges with areas make an angle of 90°)
- rough
- trimmed (a butt with an area make an angle of 90°)
- untrimmed
Sawn Timber Divided By Tree Species
- conifer
- broadleaved
- hard
- soft