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.
A specially equipped pathway (tractor track, chute, yarder line) along which timber is carried to a landing.
See “strips”.
Tight strip of sheet formed from the removal of defective parts during rotary cutting or in other operations, which is recovered by jointing.
Adhesive characterized by high strength and durability. It is suitable for use in bonding structural elements.
Qualitative and comparative index given by the ratio of the weight (or density) to the performance (or strength or stiffness value) of a material. A low value of the ratio (low weight against high performance) expresses good efficiency, while a high value indicates poor efficiency.
Classification of timber elements according to the type of loading condition (compression, traction, bending…) required to classify their strength.
A panel that contributes to the load-bearing capacity of a structure and meets the strength, stiffness and durability requirements defined by a standard or technical specification. The term is also used to indicate panels tested and certified by an independent and officially recognised Organisation for specific structural applications.
Ensuring that the structure or parts of it do not collapse under the expected load.
The load-bearing elements of a building or civil engineering work and how these elements are supposed to perform for modelling purposes.
Timber suitable for the construction of frames and strong structures. It is valued mainly for its strength.
Sheet from plywood or core plywood or for other fabrications for which good mechanical properties are required, contrasting with decorative sheets.
An organised combination of interconnected parts designed to achieve adequate rigidity. This term refers to load-bearing elements.
Upper part of a layer with an irregular shape that results in a three-dimensional surface. These surfaces are not intended to be podo-tactile.
Beam subject to compressive stress placed obliquely under a corbel or between the king post and the rafter of a truss.
Portion of the plant, part below ground and part above, that remains after felling.
Sawn timber or panel to be fixed on joists and on which a finished floor will then be laid.
See “bark beetles”.
Differentiated genetic entities within the species, i.e. subspecies, varieties, races, ecotypes, etc.
Material, usually a wood-based panel, to the surface of which an adhesive is applied in order to make a bonding or coating.
Branch or shoot developed on the trunk or other branches from adventitious or latent buds.
Wood species Scientific name: Pinus lambertiana Dougl. Origin: North America
Wood species Scientific name: Cryptomeria japonica (L. f.) D. Don. Origin: East Asia, cultivated in Europe.
Change in the color on the surface of the piece of wood due to exposure to sunlight. The discoloration is superficial and different from stain.
Deflection on the surface of plywood panel in correspondence of a joint in an inner ply or core (in the case of a core plywood) which split apart due to defective joining or shrinkage of the spliced ply. This is one of the causes of the “depression” defect.
A process involving no specific procedure to overcome the natural resistance of wood to the penetration of a preservative in its ready-to-use form. Note: Such processes include brush and spray techniques, as well as short immersion processes in which the wood is generally in contact with the preservative for only a few minutes.
Drying process in an atmosphere of pure water vapor (saturated or superheated vapor) at temperatures greater than 100°C or less than 100°C with pressure below atmospheric pressure (partial vacuum).
A person who is responsible for the product or service and ensures that quality assurance is applied: manufacturers, distributors, assemblers, service organizers, etc.
Quality control of the material, including analytical checks, which are carried out before the waste is delivered to the recycler.
Structure suitable for holding the support skyline off the ground by means of a box. It allows the carriage passage.
Part of the box that holds the skyline.
Nonunified term sometimes used to refer to plywood that is intended to be used as a support for a subsequent coating applied by further pressing. It is therefore a plywood whose faces have grain parallel to the minor dimension of the panel.
Surface on which the wooden floor is laid.
Outer part of an assortment, semi-finished product or product. In plywood, it is the visible part of the outermost sheet of a panel.
Blue stain that can be removed with a mere planing (conventionally, it is defined as “superficial” if it does not exceed 2 mm in depth).
Partial separation of major anatomic elements (fibers or tracheids) in a parallel way to the grain of a semi-finished product or wood-based panel mainly caused by stresses related to environmental exposure and aging. Generally, a fissure is considered superficial if it disappears after planing (must be approximately less than 2 mm deep)
Color alteration or staining of timber surfaces and ends.
See “surface discoloration”.
Treatment affecting the outermost layers of wood
A condition of the surface of layers or plywoods whereby a surface refractory to bonding occurs due to drying defects or hot pressing.
Application of a material with coating functions on the surface of a panel or other product.
Moisture on the surface of the sawn timber, panel or product.
Treatment that involves applying a wood preservative to the surface of the wood, usually by brushing or spraying.
Examination of a structure for determining its geometry, details and condition.
Examination performed by a recognised and qualified expert for the purpose of obtaining and validating a specific assessment and finding.
Economic activity compatible with proper management of the environment and preservation of its resources for future generations. Major Socioeconomic Policy Coordinating Institutions (FAO, World Bank, various Local Organizations) have long been promoting the use of decision-making tools based on the principles of sustainable development according to which: – the net consumption of a resource should not exceed its regenerative capacity; – the amount of waste produced (net of any recycling) must be less than its biodegradation capacity and must not cause accumulation; – the production of goods must not result in irreversible alteration of the ecosystem; – production must optimize (in economic terms) the efficiency of available resources. In this context, the entire wood supply chain faces great opportunities, but also great responsibilities in applying the above principles.
Type of setting performed by tracing each individual tooth of the blade deforming it so its cutting edge increases in width.
See “sweep”.
Deviation of the longitudinal axis of round wood from a straight line.
Wood species Scientific name: Castanea sativa Mill.
Dimensional change in wood caused by moisture absorption. If it is referred to a precise anatomical direction, it is called radial, tangential or axial swelling.
It is obtained from the ratio of total swelling to the moisture value at the fiber saturation point. It expresses swelling according to a given anatomical direction per percent point of moisture increase.
Irregular grain generally surrounding knots or crotches.
Wood species See “Swiss mountain pine”.
Wood species See “Swiss mountain pine”.
Wood species See “Swiss mountain pine”.
Wood species Scientific name: Acer pseudoplatanus L., Acer platanoides L. The wood of the two different wood species is traded without distinction.
Set of activities related to forest management and aimed at its renewal.
Synthetic substance used in the repair of small defects on the surfaces and/or edges of semi-finished products and wood-based panels. It usually consists of a mixture of resin, wood flour, oxides or pigments. It is applied by spreading with a trowel or special scraper in an operation known as “puttying” and usually precedes sanding. The putty can be single- or two-component and often pigmented in such a way to match the color of the wood on which it will be used.
Attestation by an independent third party of the conformity of a company’s quality system to specific standards. This usually refers to the international ISO 9000 standards (until December 94 UNI EN 29000, now UNI EN ISO 9000), which indicate how a company should be organised and should operate under quality assurance.
Longitudinal mark, originating in the living tree, that appears as a “T” shaped on the cross section of a log or a sawn timber.
Strength class defined by the characteristic tensile strength parallel to the grain, the grain, and the characteristic density and the mean modulus of elasticity parallel to the grain.
Property of an adhesive that allows it to form a bond of measurable strength immediately after the adhesive and the adherent are put in contact under limited pressure conditions.
Tackle in which force multiplication is achieved by a double set of blocks: one set carried by a movable block and the other by a fixed block (movable and fixed size) on which the rope is alternately returned. The driving force is applied to the free end of the rope (the other end is attached to one of the two blocks) either manually or with a winch. The driving force to be applied is the less, relative to the force produced, the greater the number of blocks.
See “tackle”.
Tool for exerting tensile forces by means of ropes.
Wood species Scientific name: Larix laricina Koch Origin: The territory of Canada and the United States stretching from the Great Lakes area to the Atlantic Ocean.
A trade name wrongly used (it is not a walnut and does not even come from Tanganyika!) to refer to the wood of Aningeria spp. from Africa (see “aniegré”).
It is one of the two main longitudinal anatomical directions. The other is the radial one. Referring to the trunk or a portion of it, it indicates a plane tangential to the growth rings. A plain sawn timber derives from a cut made along that plane.
Section obtained by a cut parallel to the direction of the grain and perpendicular to the direction of a parenchymal ray; also of the surface or anatomical section obtained by this cut.
1) Wood shrinkage in the tangential direction relative to the growth rings. 2) Wood shrinkage in the normal direction relative to the rays.
1) Wood swelling in the tangential direction relative to the growth rings. 2) Wood swelling in the normal direction relative to that of the rays.
Extractive of wood or bark with phenolic radicals. It is abundant in some tropical woods and was formerly used for tanning leather. Like phenol it is able to react with formaldehyde and form an adhesive. Due to this property it is therefore currently used as an excipient for adhesive mixtures or in the formulation of new adhesives.
Darkening of the surface of timbers containing tannins that are washed away by moisture migration during drying and concentrate on or near the surface.
See “tannin discoloration”.
Rubberised paper or textile strip sometimes applied perpendicular to the grain of wider veneers or facing sheets formed from spliced veneers. Its purpose is to facilitate handling and reduce the risk of breakage or damage during gluing and pressing.
Progressive reduction in the diameter of a trunk proceeding from the base of the plant toward the tip. This must be taken into account in mathematical formulas for calculating the volume of the trunk (usually with a parameter called the “shape coefficient” or “taper coefficient”).
Reduction rate of the diameter of a stem (or trunk) proceeding from the base of the plant towards the tip.
Sawn that, since it has not been trimmed, has non-parallel edges (and roughly trapezoidal faces). The adjective ” conical” is to be discouraged; it would be more accurate to say “tapered” or “trapezoidal.”
Carriage device of a sawing machine to align the log for tangential sawing along the grain.
A visible cut on the outside of the trunk, which is operated to extract resin in conifers (especially Pines and Larch). One of the most common types is herringbone.
Wood preservative obtained by mixing creosote with other petroleum compounds.
Average moisture content that a load of timber should have at the end of the drying process.
Retention of the reference preservative considered capable of providing an adequate level of protection against biological attack.
Desired size at the end of a given process (at a given moisture content), to which permitted deviations relate.
Systematic category of undetermined rank in botanical nomenclature such as order, family, genus, species.
Wood species Scientific name: Tectona grandis L. f. ATIBT nomenclature: Teak. Origin: Asia (Burma); cultivated in Asia, Africa and other countries.
A document that outlines the methods and procedures that must be adopted to comply with the technical rules.
Technical specifications, including the provisions that apply to them, whose compliance is mandatory “de jure” or “de facto” for marketing or use in a state or a major part of it, with the exception of those set by local authorities (Art. 1.5 Dir. 83/189 EEC). Technical regulations are issued by the public authority in the form of a law, regulation or administrative rule.
Specification contained in a document that defines the required characteristics of a product, such as levels of quality or use properties, safety and dimensions. It also includes applicable requirements for terminology, symbols, tests and test methods, packaging, marking and labeling.
Dispositions for common and repetitive uses of products or services, relative to actual and potential problems, aimed at obtaining the best order in a given context. They are recommended but not mandatory application. They must be: – accessible to the public; – developed with the cooperation and consensus of all interested parties (producers, users, Authorities); – based on the results of science, technology and experience; – representative of the “state of the art,” defined as the stage of development reached at a given time; – tending to the benefit of the community and civil progress; – approved by a nationally or internationally recognized body. They become mandatory only if expressly referred to in legal and/or administrative Acts.
Hard fibreboard treated, usually with oil or heat, to improve its physical properties.
General term including all operations intended to improve a forest or stand. Operations conducted to assist the development of a stand at any point in its life.
See “tending”.