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.
Biodeterioration caused by insects.
Tunnel carved by insects or xylophagous marine crustaceans to lay eggs.
Time from any stage in one generation of insect to the same stage in the next.
Chemical substance that has lethal effect on insects. Insecticides exert their action by contact, ingestion or inhalation.
Class of arthropods whose individuals have the body divided into three parts (head, thorax and abdomen), have of pair of antennae, three pairs of legs and one or two pairs of wings.
Insertion of a sound sheet element (patch), of a given shape, to replace defective portions of a plywood sheet that have been previously removed. This operation can also be performed on other types of semi-finished products and wood-based panels.
Replaceable tooth of a saw blade not formed by the saw body.
In a sawn timber, it is the face that was closest to the pith in the log.
The activity of measuring, examining, testing, verifying by means of gauges, one or more characteristics of a product or service in order to ascertain its conformity with specified requirements. Testing must be based on statistical criteria and can be performed with reference to variables (e.g. a mechanical resistance value) or attributes (e.g. a “yes” or “no” judgement on the compliance of the bonding quality with the specified requirements).
Any person authorised by the Commissioners to act as inspector for the purposes of the Plant Health (Forestry) Order 2005.
Provision that establishes an action to be performed.
A particle or fibreboard with low thermal conductivity and density. Its thickness is around 10-25 mm.
Tubular intercellular space of indeterminate length, generally with a function to contain resin, rubber, etc. It may be axial or radial (within a radius). The ones of traumatic origin are often abnormal in size.
Intercellular space of limited length with function as a deposit of resin, gum, etc.. It is generally formed as a result of trauma to the living plant.
An isotropic cellulose-free layer between adjacent cells. Corresponds to the “middle lamella.” Note: The intercellular layer often passes imperceptibly into the primary cell walls and special techniques may be needed to highlight it.
Space between cells. Two types can be distinguished: – secretory: includes intercellular channels and intercellular cavities, which may be schizogenic, lysigenic or schizo-ligogenic; – non-secretory: interstitial space.
Knot tightly connected for at least 3/4 of its perimeter to the surrounding wood (or semi-finished product).
Irregular growth that assumes a different direction at different times.
A singularity in wood whereby the main anatomical elements (fibres or tracheids), in successive growth portions, are alternately inclined in the opposite direction to the growth axis of a stem or to the surface of a semi-finished product. Interlocked grain can determine stripe figure effect.
In wood flooring, an assembly system based on a tongue-and-groove profile.
Cuttings that are made during the course of the shift by carrying out the necessary tending such as intermediate treatment, thinning, suppression of supernumerary plants, clearing and pruning. The resulting products are similarly called “intermediates.”
Intermediate cuttings carried out during the novelleto stage in order to decrease stand density, especially in the case of natural or artificial seed regeneration.
Inner layers of sapwood that are transitional between sapwood and heartwood in color and general characters. It is also called “transition wood.”
Stress induced on test samples from particle and fiber panels in order to determine the quality of their bonding. It is interpreted as the tensile strength perpendicular to the faces provided by the unit elements constituting the panel. In addition, it is influenced by the amount of interconnections that develop in the formation of the mat.
Color alteration or staining not visible on the surface or ends of timber. It is produced during the drying process.
See “internal discoloration”.
Primary phloem internal to the primary xylem. It is also called “perimedullary phloem”.
A sample recognised by international agreement as an international basis for setting the value of all other samples of the size in question.
Acronym for “International Standards for Phytosanitary Measures.” It is a Standard developed by IPPC/FAO concerning the phytosanitary measures to which wood packaging must be subjected in international trade.
Voluntary technical standards developed and released by ISO (International Standards Organization), consisting of representatives of national standards bodies from more than 180 countries.
Interface documents between a European Directive and the technical standards drawn up by CEN. Their purpose is to guide the drafting of standards with regard to compliance with the essential requirements set out in the Directive.
Non-secreting space between cells.
Term used: (a) In a broad sense, for pits between tracheal elements; (b) in a narrower sense, in wood anatomy for pits between vessel elements.
Document showing the bill of goods sold, or a description of the service rendered, and the amount involved.
Wood species Scientific name: Milicia sp.p. (M. excelsa) ATIBT nomenclature: Iroko. Origin: West and East Africa.
Laying geometry of parquet.
Thickness exceeding tolerances on nominal value.
Standards for a supplier’s corporate quality system. This is a group of standards, of which three (9001, 9002, 9003) concern the contractual conditions in the relationship between supplier and purchaser, and one (9004) concerns the criteria for running the company and its internal organisation to operate with a view to quality. Transposed by CEN as EN ISO 9000 standards and by Italy as UNI EN ISO 9000 standards.
Removed or detached bark from a live, felled or fallen tree or any part of a tree.
Social insects divided into several families. In Europe only four species are significant. Among them, the most dangerous to buildings are the subterranean ones, mainly Reticulitermes lucifugus and Reticulitermes santonensis. In Europe, termites are found only in certain limited geographical areas. In these areas, the use of wood preservatives in termite control is supplemented by the adoption of other protective measures for floors, foundations and walls.
Material in which the values of properties measured along different reference axes are nearly identical. An isotropic material therefore exhibits homogeneous properties in all directions.
Wood species See “italian stone pine”.
Wood species Scientific name: Pinus pinea L.
Wood species See “italian stone pine”.
Standard developed and issued by the Italian standardisation body, i.e. UNI (CEI for the electrical sector). It has emanated numerous standards in almost every sector and participates in European standardisation activities within CEN.
Wood species Scientific name: Pinus banksiana Lamb. Origin: North America
Veneer for use as a base for face veneer in double veneering.
Wood species Scientific name: Fraxinus mandshurica Rupr. Origin: Japan, China.
Insects belonging to the order Coleoptera that burrow tunnels into decaying plants or wood.
Art, carpenter’s craft.
Any joining of two or more pieces of wood performed by gluing, interlocking, nailing, screwing, etc.
Joint strength expressed as a percentage of solid wood strength (without joints).
Core with machined and squared edges. Spaces between core pieces should not exceed 18 mm, and the average of all spaces in the panel should not exceed 5 mm.
In plywood, internal ply consisting of veneer strips joined together to recompose the dimensions of the finished panel. This operation is performed to facilitate the composition and improve the panel’s characteristics.
Small beam used to support a floor or ceiling. Usually the joists are arranged in parallel series that are supported in turn by beams or load-bearing walls.
Central part of the xylem surrounding the pith in young trees or tissues near the stem apex. Cells have low density, smaller size and/or less evolved structure than cells in outer parts of xylem or older parts of stem.
Wood species Scientific name: Dryobalanops sp.p. ATIBT nomenclature: Kapur. Origin: South-Est Asia
Wood species Scientific name: Koompassia malaccensis Maing. ATIBT nomenclature: Kempas. Origin: South-East Asia.
The mark left by the blade during sawing. It is slightly wider than the width of the blade itself.
Bending of a piece of wood executed by performing a series of parallel cuts along the entire thickness of the wood so that it can be curved toward the worked side.
Wood species Scientific name: Dipterocarpus sp.p. ATIBT nomenclature: Keruing. Origin: South-Est Asia
Wood species Scientific name: Khaya sp.p. ATIBT nomenclature: Acajou d’Afrique. Origin: West and East Africa.
Abrupt stop of the saw, causing it to wheel over the workpiece, due to overfeeding of a tooth. Note: also for irons of peeling lathes, shears, planers, etc.
In chainsaw use, it is an uncontrolled (sudden and accidental) upward or backward movement of the bar that can occur when the tip of the bar comes in contact with a body (log, branch, or stump) or when the wood tightens the chain during cutting.
In pressure processes, amount of impregnant that leaks from the wood after the final vacuum is applied.
Timber drying kiln with temperature, humidity and airflow control.
Procedure through which the moisture content of wood is reduced in order to improve its performance. It can be carried out by exposure to air in an outdoor environment under cover (in which case it is called ‘air seasoning’) or artificially through the use of a drying kiln in which it is possible to generate a heated environment, change the relative humidity, ventilation and possibly the air pressure.
Timber that has had a drying process by which, through appropriate control of temperature, relative air humidity, ventilation, and possibly atmospheric pressure, reaches a moisture content compatible with its intended use. Semi-finished products are usually dried before gluing.
Central element of the trusses.
Wood species Scientific name: Paulownia tomentosa Stend. Origin: Japan and China; cultivated in other countries as an ornamental species.
Timber dried in a kiln usually at a previously defined moisture content.
Drying of wood in closed chambers, tunnels or cylinders in which the drying condition can be determined, controlled and regulated.
Cutting organ featured in many machines used in the wood industry. It has various configurations depending on the different processing modes: peeler knife, clipper, slicer, chipper, planer, etc.
In veneer peeling lathes and shearing machines, it is the angle that the back of the knife forms with the plane that passes through the knife edge and is parallel to the guides. The angle is measured towards the workpiece being cut.
In rotary cutting, it is the distance between the two planes parallel to the knife guides, one of which passes through the cutting edge and the other through the log core.
Linear ridge produced transversely on a ply of plywood by a defective action of the pressure bar or knife.
Basal portion of a branch encased in a stem or semi-finished product. The density of the wood constituting the knot is greater than that of the surrounding wood and the direction of the grain around the knot is deviated. Furthermore, as the wood tissues are oriented differently, during the drying process the knot shrinks in a different way from the surrounding wood. Besides their aesthetic appearance, knots can change the mechanical characteristics of the product and its finishing possibilities. For these reasons, knots generally constitute a defect.
Knots sufficiently close together that normal grain does not reconstitute in the space between them. Conventionally, the distance between two adjacent knots should be less than the width of the sawn timber or, if that width is greater than 150 mm, it should be less than 150 mm. It is also called “knot cluster”.
See “knot cluster”.
Gap caused by the exit of a non-adherent knot from a semi-finished product.
See “knot hole”.
Area surrounding a knot on the surface of the round wood where a branch, local swelling, and bark have been roughly cleared.
Staining on the peripheral surface of round timber surrounding a node where the branch, bark, and associated local swelling have been cut.
Quality, appearance or consistency related to the presence of knots.
Wood species Scientific name: Pterygota macrocarpa. Origin: West Africa
Wood species Scientific name: Anisoptera sp.p. Origin: Southeast Asian tropical zone.
Formal recognition of a laboratory’s suitability to carry out specific tests or certain types of tests. In the absence of a reference law, it is now carried out by SINAL, which verifies the laboratory’s compliance with the UNI CEI EN 45001 standards.
Examination of a testing laboratory to assess whether it qualifies for accreditation.
Person who executes part or all of the functions related to the laboratory assessment.
Measurement of the face of the laid element.
Advanced stage of rot caused by basidiomycetes in which wood decays into longitudinal lamellae that split along growth rings.