A simple and accessible tool for understanding the fundamental terms related to wood. From the meaning of sapwood and heartwood to the characteristics of texture, grain, and density. A useful resource for professionals, citizens, and students who want to familiarize themselves with the language of the sector.
Conversion of products from primary manufacturing into further manufactured products such as doors, window frames, furniture components and a wide variety of other consumer products. It is a more generic and sometimes less specific term than ‘remanufacturing’ as its validity extends from raw semi-finished to finished products.
Normally the part of the bark formed by the cambium. It is also called the “secondary sieve”.
In wood anatomy, ray derived from cambium (i.e., originating after secondary wood formation) and not extending inward to the pith.
Categories or wood species that, while lacking the intrinsic value and commercial reputation of primary timbers, are currently or potentially marketable.
Wood produced by the cambium. It is also called “secondary wood.”
Nailing or screwing through the tongue or groove of the elements. This laying system makes the upper sides of the elements hide the fastening points.
Part of the fruit derived from the fertilised ovum and containing the embryo which, upon germination, originates a new plant.
A sale under a public tender procedure with successive increased bids.
A sale in which the price is set according to the weight of the goods.
Timber sale method prior to felling, in bulk or by measure, with harvesting costs borne by the buyer.
Testing of a timber element whose impact on its load-bearing capacity or appearance is minimal.
A product to be further processed before its final marketing (e.g. a raw wood-based panel to be coated with a decorative material for the production of a piece of furniture).
An adhesive consisting of two components that are applied separately to the two surfaces to be bonded. When the two surfaces are brought into contact, the two parts promote the polymerisation reaction.
In a plywood, this term indicates an open joint at the load of an external ply.
Fibro-tracheid with thin walls across the lumen. Note: In these elements, the protoplast divides after secondary wall formation.
Axial or radial parenchyma cell with one or more thin septa across the lumen.
Fiber with thin transverse walls across the lumen. Note: In these elements, the protoplast divides after the formation of the secondary cell wall.
Wood species See “meranti”
Fungus belonging to the Basidiomycetes. It causes brown rot.
Operating situation characterized by homogeneous thermohygrometric conditions, whwere by Eurocode 5 provides correction factors for the characteristic values and deformations of a wooden material used for structural purposes. The different classes are defined as follows: Service Class 1: is characterized by a material humidity corresponding to a temperature of 20°C and a relative humidity of the surrounding air exceeding 65 % only for a few weeks per year. Under such conditions, the average humidity in most softwoods (solid wood) will not exceed 12 %; Service Class 2: is characterized by material moisture corresponding to a temperature of 20°C and a relative humidity of the surrounding air exceeding 85 % only for a few weeks per year. Under such conditions, the average humidity in most softwoods (solid wood) will not exceed 20 %; Service Class 3: is characterized by climatic conditions that result in higher humidity than those of Service Class 2. Covered structures should be considered as belonging to Service Class 3 only in exceptional cases. The system of Service Classes is mainly intended for assigning strength values and calculating deformations of wooden structures under certain environmental conditions. The Service Classes are in principle harmonized with the thermo-hygrometric conditions of the biological attack risk classes, even though the two systems use different criteria to achieve different purposes.
Service class 1 is characterised by a moisture content of the wood material, corresponding to a relative humidity of the air (at a temperature of 20°C), which only exceeds 65% for a few consecutive weeks per year. Under these conditions, the representative moisture content for solid structural softwood timber is 12%. This class corresponds to a dry environment. In this class, elements in an insulated environment and heated buildings are included.
Service class 2 is characterised by a humidity of the wood material, corresponding to a relative humidity of the air (at a temperature of 20°C), which only exceeds 85% for a few consecutive weeks per year. Under these conditions, the representative moisture content for solid structural softwood timber is 20%. This class corresponds to a humid environment. In this class, elements in uninsulated rooms and unheated buildings are included.
Service class 3 is characterised by a moisture content of the wood material, corresponding to a relative humidity of the air (at a temperature of 20°C), which only exceeds 95% for a few consecutive weeks per year. Under these conditions, the representative humidity for structural solid softwood timber is 24%. This class corresponds to an outdoor environment that is not in direct contact with soil or water. In this class, elements exposed to adverse weather conditions and with limited re-drying capacity are included.
Service class 4 is characterised by a moisture content of the structural timber element corresponding to a saturated condition and affected by the surrounding environment. This class includes elements in direct contact with soil and water (e.g. foundation piles and marine structures).
Conformity assessment of the structure or parts of it to the limit states specified for the service conditions.
The distance between the projection of the protrusion of the tip of a saw tooth set by the kerf and the face of the saw blade.
Mechanism in the carriage of a sawing machine that enables the adjustment of the position of the uprights carrying the clamps that grip the log in order to orient the log toward the saw blade in the most appropriate way. Note: This operation is called orientation; the French term also includes log disengagement operations.
See “set”.
Transformation of an adhesive from a fluid to a solid state by chemical or physical action or both. It is also used as a synonym for “curing” although the latter more accurately indicates a transformation by chemical action while the term ” set” implies a physical action such as the loss of solvent (which usually occurs by evaporation). The term “hardening” is less specific and rarely used.
Localised change in the size of a piece due to internal stresses or impediments to normal shrinkage during the drying process.
Treatment of bent timber to maintain its bending.
Set of operations that establish, under specified conditions, the relationship between the values indicated by an instrument or measuring system or the values represented by a material sample and the corresponding known values of a measurand.
Maintenance operation necessary to make the blade of a saw create, as it advances through the wood, a groove wider than the thickness of the blade itself, which would otherwise be affected by excessive friction during cutting and might even become stuck. The two classic forms of setting are binding and swaging .
Size according to which the machinery is calibrated to provide sawn timber of a given effective size. Note: Usually this dimension includes an oversize to account for any processing imperfections and shrinkage phenomena in the sawn timber.
Appropriate tool for connecting blocks, tackles or guy wires to the skyline of yarder.
See “growth temperament”. Not to be confused with ‘ombrophytes’ which are the species adapted to rainy conditions or habitats.
Resistance of a material or structure to weather-induced deformation.
Generally, it is any processing with rotating knife machines, on the edge or extreme edge of a workpiece.
Arris without wane.
Square timber (mostly beams or sawn timber) with regular edges and without bevels or rounded edges.
(a) In the case of a rotary blade or a circular saw tooth, it is the angle (in the plane perpendicular to the axis of rotation) formed on one side by the attachment face or attachment bevel of a tooth or blade and on the other side by the rake face or rake sharpening (rotary blade) or by the back bevel of the tooth or the bevel of its rake face (saw blade); (b) In the case of a band saw or reciprocating saw or an orthogonal cutting edge iron, it is the angle (measured in the plane of the band or blade or a plane perpendicular to the faces of an iron) formed on one side by the face of attack or the attachment bevel and on the other side by the back of the tooth or the rake bevel; (c) In the case of the pressure bar of a sheeting machine, it is the angle formed by the two faces of the bar and is the edge that applies pressure to the periphery of the log being rotary cutted.
Woody particle of various sizes that has a peculiar structure due to the mode of production. It is in fact a by-product of surface cutting operations carried out moulder. The cutting action produces a fine particle of varying size from edge to edge and generally curled.
A condition of tension or deformation in which parallel planes slide relative to each other.
Damage on the end of the round wood, occurring in the course of felling or cross cutting.
Interlocking device between two elements that transfer shear force into the joint plane. The elements are kept in position with dowel-type fasteners.
A load that a material is able to withstand when subjected to a shear stress. It is measured as shear failure load referred to the unit area. In the case of wood-based panels, a distinction is made between: – shear strength in the plane (planar shear), being parallel to the faces, in correspondence with the inflexed parts of the panel; – shear strength in the thickness (panel shear), being perpendicular to the faces, in correspondence with nail, screw, pin, or glue unions or flanges that undergo lateral offset (e.g.: in the case of a panel used as a diaphragm in a wall).
Cell of a series of erect cells tending to form a sheath at the procumbent cell margins of a multiseriate ray seen in tangential section.
Structural sheathing, usually consisting of wood panels or boards, on the exterior surfaces of the framing. It is used to support the construction, snow and wind loads, and provides support for the attachment of exterior cladding materials (such as wall coverings, roof tiles, or underlayment of double-layered floors).
Period of time in which the work time required to carry out a given activity is divided according to periodic rotation criteria.
Portion of a sheet, narrow and elongated in shape, intended for the repair of plywood. The same term is also used for other semi-finished wood-based products (e.g. sawn timber, solid wood panels, etc.).
Very thin board of wood (usually Larch) typically obtained by splitting, used to make roof covering especially in mountainous areas.
Short section of log used for making shingles.
Timber for shipbuilding and nautical construction.
Timber which has been predried at sufficiently low humidity, often specified, for the purpose of eliminating the risk of staining, mold, and degradation during transport.
Wood that has been brought to a sufficiently low moisture content to limit the development of biodegradation agents during transport.
Marine borers of the genus Teredo
Nonunified term sometimes used to refer to a nonconforming panel whose related defects have been removed resulting in a change in its original dimensions.
A panel that does not fulfill the minimum requirements estabilished by reference legislation or contractual agreements due to defects generally different from the quality of the gluing.
Cultivation, on agricultural land, of fast-growing tree species with high planting density (10-15,000 plants/ha). Frequent coppicing in the short term (1-6 years) and cultivation techniques similar to those used for agricultural crops are practiced.
A system for applying a surface coating to a backing panel using a highly reactive thermoplastic adhesive (quick-setting) characterised by a high level of automation to ensure high productivity.
Trade name for round or sawn timber (in this case often made from the sides of logs) with a length of less than 3.90 m (i.e. that of classic coniferous saw timber).
Dimensional change in wood caused by moisture decrease. If it is referred to a precise anatomical direction, it is called radial, tangential or axial shrinkage .
It is obtained from the ratio of total shrinkage to the moisture value calculated at the saturation point. It expresses the shrinkage with respect to a given anatomical direction per percent point of wood moisture reduction.
Vegetable with a shrubby habit.
A block on which the mainline, haulback, and auxiliary ropes run and are deflected. It can be subjected to high rope speeds.
First sawn timber obtained from the outermost part of the log (immediately after the slab).
See “xylem”.
Depressed surface in the wall of a sieve tube member perforated by a cribro-like group of minute pores through which the protoplast results in contact with that of a contiguous sieve tube member. It is also called a “cribrous field.”
Long, thin phloem conducting cell. Not part of the sieve tube, but has relatively unspecialized sieve areas especially at the sharp ends which overlap with those of other sieve cells.
Arrangement of small pits in sieve-like groups.
Specialized part of a sieve tube member’s cell wall with a solitary sieve area (simple sieve plate), or several neighboring areas, often with scalariform or reticulated arrangement (compound sieve plate).
Phloem conducting tube formed of an axial series of sieve tube members.
Elongated conducting phloem cell part of an axial series of cells arranged end to end to form a sieve tube. The common walls, which may be sloping or transverse, form the sieve plates; sometimes with less specialized sieve areas in other parts of the wall as well.
Striations of shiny appearance, irregular in shape and different in color from the background (lighter in oak, darker in sycamore and beech) due to traces of parenchymal rays. They are clearly visible on the surfaces of the aforementioned woods obtained by radial longitudinal cutting. In Tuscany, the pronounced silver figure of oak wood is also called “slumacature.”
Wood species Scientific name: Abies alba Mill.
Deformation consisting of a single bow.
Joining two pieces of wood without gluing or mechanical connection.
Outer layer of sliced or peeled veneer that is glued to each face of the core.
Single and generally large, more or less rounded opening in the perforation plate.
Pair of two simple pits of adjacent cells.
Deformation consisting of a single spring.
Curvature having only one deflection.
See “simple sweep”.
Simultaneous, instead of sequential, closure of all the plates of a multi-daylight press.
Knot sufficiently distant from other knots that it does not form a group with them (see “group of knots”).
Solid wood panel consisting of numerous pieces of wood glued together to form a layer. A panel is called a “solid wood panel with pieces cut lengthwise” if it consists of pieces that have cuts lengthwise and, usually, either glued at the end or joined by finger joints. On the other hand, the term “solid wood panels with pieces not cut lengthwise” is used if the pieces are undivided along the entire length of the panel.