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.
Acronym for “Programme for Endorsement of Forest Certification schemes.” It is a certification body for the sustainability of forest management.
A cylindrical bar with a circular cross-section, usually made of steel (but may also be made of other metal, plastic or wood), forcefully inserted into a pre-drilled seat to transmit loads perpendicular to the peg.
A cylindrical piece of wood pointed at one end, designed to penetrate and be integral to mostly support functions.
Biofuel obtained from pulverized and compressed biomass, with or without the use of pressing additives. It has a cylindrical shape, random length typically between 5 and 30 mm, and irregular ends. The raw material used for the production of pellets can be woody biomass, herbaceous biomass, biomass derived from fruits, or a union and mixture of different types of biomass.
A process consisting of procedures aimed at bypassing the natural resistance of wood to the penetration of a preservative in its ready-to-use form. NOTE: Examples of such processes include the technologies currently practised of diffusion treatment, the double vacuum process and the vacuum/pressure process.
Depth of penetration of an impregnating liquid into the wood.
It is the minimum depth to which the active ingredient(s) of the wood preservative is intended to penetrate into the wood.
Also called “percent wood fibre failure”, it indicates, in determining the bonding quality of a plywood, the area of the tested glue line covered with wood fibers. It is determined by visual examination after the tensile shear strength test. It is expressed as a percentage of the surface area of the area under test.
See “percent cohesive wood failure”.
Aperture (single or multiple) in the end wall of vessels. It allows the passage of fluid between adjacent cells.
Conventional term for the area of the vessel wall (originally unperforated) involved in the joining of two elements of a vessel.
Residue of a perforation plate forming an edge around a simple perforation.
Panels classified according to certain performance requirements related to their final use.
Layers that replace the epidermis and form an impermeable covering of older roots and stems. It consists of the phellem (cork), phellogen, and phelloderm.
The whole set of operations that mostly take place through the intermittent action of knives: it includes sawing, planing, moulding, milling, mortising, etc., as opposed to peeling and slicing.
The deformation of a piece of wood that has been stressed further than its elastic limit.
Easiness of liquids or gases to pass into or through a material.
Wood whose sapwood and/or heartwood belong to impregnability class 1 as defined in EN 350-2.
See “permitted deviation”
Set of upper and lower deviations. They are each defined as the algebraic difference between the maximum (or minimum) effective measure and the desired measure (upper and lower). If the upper and lower offsets are different, the desired measure should be given in this way: 50 (+3; -2) mm. If, on the other hand, the two deviations are the same, it is indicated, for example, 50 ± 2 mm.
Evolutionary stage of an even-aged forest from canopy closure to culmination of height gain.
Any species or biotypes of plants, animals or pathogens that are dangerous to plants or plant products. Note: In IPPC, the term “plant pest” is sometimes used instead of “pest.”
Probability of introduction and spread of a pest with the potential associated economic consequences.
It is the evaluation process of biological or other scientific and economic evidence for determining whether an organism is a pest, if it needs to be regulated, and the level of phytosanitary measures to be adopted against it.
Process of replacing the organic substance of wood with an inorganic one through the deposition of mineral substances within the lumens and cell walls. It is usually caused by calcium carbonate, silicon oxide and phosphates. The contact between wood and metals during their oxidation process results in mineralisation by oxides and oxide hydrates.
Tissue produced by phellogen externally in a stem or root. Cell walls are generally suberized, and in thick-walled types, additional lignified layers can be found toward the cell lumen. The non-suberized cells of the phalleme are known as phelloid cells.
Tissue generally resembling cortical parenchyma in appearance, but consisting of the cells produced from the phellogen inward. In woody trees the cells may enlarge and thicken to form stony cells sometimes elongated radially.
Meristematic layer that produces periderm.
Petroleum-derived synthetic adhesive used for bonding, by hot pressing, plywood panels and products and other wood-based products. Properly performed bonding with a mixture of phenolic resin-based adhesives satisfies the requirements for outdoor use of panels. The glue line generally has a dark coloration.
It is the main nutrient conducting tissue in vascular plants. In the stems of most dicotyledons and angiosperms it is separated from the wood (xylem) by the cambium from which it is generated.
Cell produced outward from a fusiform cambial initial. It undergoes further periclinal division before differentiating into a phloem cell.
Parenchyma present in the phloem. It is also called “Sieve parenchyma.”
Part of the ray external to the cambium.
Wood species Scientific name: Juniperus phoenicea L. (Sabina phoenicea Ant.).
Surface degradation of wood caused by photo-oxidative processes generated by long-term exposure to sunlight or UV radiation.
Official operation (for example, inspection, testing, surveillance, or treatment) conducted to implement phytosanitary measures.
Official paper document or its electronic equivalent, in accordance with the IPPC’s model certificates, which certifies that a consignment meets the phytosanitary requirements for import.
Specific phytosanitary measures imposed by an importing country regarding consignments entering that country.
Any official legislation, regulation or procedure aimed at preventing the introduction or spread of quarantine pests or limiting the economic impact of regulated non-quarantine pests.
Any official method for the implementation of phytosanitary measures, including the execution of inspections, tests, surveillance or treatments in relation to regulated pests.
Preservation of the integrity of a consignment and the prevention of its infestation and contamination due to regulated pests by the application of adequate phytosanitary measures.
Determination of volume by measuring the thickness (with or without bark) and length of each piece of wood.
Electrical polarization induced in a crystal by the application of mechanical stress. Since the cellulosic component of wood has crystalline structure, it highlights this effect. Furthermore, since in wood there is a valid relationship between values of density and modulus of elasticity, the effect can be exploited for the purpose of nondestructive characterization of the material.
See “stacked volume”.
Usual name under which the wood is most commonly commercialized and which has been adopted either by the main exporting country or the main importing country. Note: Pilot names have been established in the ATIBT nomenclature since 1954.
Round or oval, sound, adherent or partially adherent knot not exceeding 5 mm in size. (The French term is also used for round timber, see “epicormic shoot”).
Insect hole with diameter less than or equal to 2 mm.
Holes and tunnels in wood whose walls are dark due to the presence of fungi that provide nourishment for the larvae.
Species that prepare the soil for the establishment of more demanding and definitive species.
Cavity in the secondary wall of a cell open internally to the lumen, along with its outer closing membrane. Pits are meant to connect adjacent cells (either a vessel with another vessel or a vessel with a ray), hence they are generally paired. There are various types (areolate, blind, cupressoid, fenestriform, linear, piceoid, pinoid, branching, simple, taxodioid, dressed).
Opening of a pit. Terms used to describe pit aperture are: – coalescent: slit-like openings joined to form channels on the inner surface of the secondary cell wall; – debordant: internal openings whose contour, in surface view, extends beyond the contour of the pit border. – external: pit channel opening in the pit chamber; – included: internal openings whose contour, in superficial view, is included in the contour of the pit border; – internal: opening of the punctuation channel in the lumen of the cell; – lenticular: slit openings with the appearance, in superficial view, of a double-convex lens seen in section.
The domed part of the secondary cell wall in an areolate pit.
Passage from the cell lumen to the chamber of an areolate pit. Note: Simple punctuations in thick walls generally have channel-like cavities.
The whole space in a pit, from the membrane to the lumen.
Space between the pit membrane and the overlying domed border.
The part of the intercellular layer and primary cell wall that externally confines the pit cavity. The central, thicker part of the membrane is called the torus. Note: A torus with a dentate or hemmed margin, as in Cedrus, is known as a dentate torus.
Round wood, often roughly squared, intended for support structures in mine workings.
Device equipped with smooth and grooved rollers, for guiding and dragging wooden semi-finished products to be resawed.
Special type of band saw used for reworking workpieces that have at least one flat face. It is mainly used to recover thin sawn pieces from the sawlogs obtained with the main saw.
Pair of complementary pits of adjacent cells.
In a knife of a chipless cutting machine, it is the angle that the plane of the knife’s leading edge forms with a given reference plane. The longitudinal pitch is the angle between the direction of the wood grain and the surface of an oblique cut, intermediate between a cross cut and a cut for the long run. The transverse pitch is the angle of incidence between the direction of the wood grain and the surface of an oblique cut, intermediate between a transverse cut and a longitudinal transverse cut.
Wood species See “pitch pine; Carolina, Caribbean”.
Wood species Collective name under which certain timbers of species vegetating in North America and Central America are included, whose scientific names are as follows: Pinus Caribaea Morelet Pinus elliottii Engelm. Pinus palustris Mill. Pinus taeda L. Pinus echinata Mill.
Small, soft portion, usually cylindrical in shape, often present in the centre of the cross-section of a stem. It is generated during the early stages of the tree’s growth and corresponds to the position of the vegetative apix.
Check that occurs in a wooden board between the surface and the center of the pith.
Characteristic appearance of a stem in which the pith is displaced compared to the geometric center of the section
Irregular bead of abnormal parenchymatic tissue (often of traumatic origin) immersed in wood. It appears on tangential surface as a streak. It is commonly caused by the cambium miner larvae.
Woody assortment used as support poles in mining.
The supply by any means, regardless of the sales technique used, of timber or timber products for the first time on the domestic market for distribution or use in commercial activities, whether in return for payment or free of charge. Internal market means that timber is physically present in a particular country, where it is harvested or imported and cleared for free circulation. Goods subject to special customs regimes (e.g. temporary importation, inward processing, processing under customs control, customs warehouses), in transit transit or being re-exported are not considered to be placed on the market.
Sawn timber having a face perpendicular to the rays. If the rays are not visible, it can be defined as sawdust having a face tangential to the growth rings.
Sawn timber in which one of the faces is at least approximately perpendicular to the parenchymal rays; if the rays are not evident, it can be recognised because one of the faces is at least approximately tangential to the growth rings.
Structural element with two dominant dimensions (wall, floor or roof).
Wood species Scientific name: Platanus occidentalis L. and Platanus orientalis L. Origin: Europe and North America (P. occidentalis); Italy, southern Balkan Peninsula, western Asia, Himalayan mountain slopes (P. orientalis).
Which has undergone planing. See ‘planing (work)’.
Sawn timber that has been processed (at the end-use moisture) along its entire length and width on at least one face in order to obtain a smooth surface.
Machinery used for planing.
Operation consisting of obtaining a flat reference surface (surface planer) and eventually bringing a sawn timber to the desired thickness (thickness planer).
A factory dedicated to planing work or even milling and molding; mostly each factory is dedicated to the production of certain manufactured goods such as planks, etc.
Board used for coatings. It is planed on one face and usually has tongue-and-groove joints on the longitudinal edges. The most common dimensions are: thickness: 12, 15, 20 mm width: 120, 150, 200 mm length: 4000 mm
Covering a wall with small boards, known as planks.
Sawed timber of high thickness.
Structure consisting of boards or axes placed side by side and committed in various ways to serve as a floor, wall, roof, partition.
Study of the interactions that exist between plant individuals and their environment, as well as the factors influencing the environment.
Plant scheme that defines the reciprocal distance between the different trees (for example, along the row and between the rows of trees of the same species).
Term used to refer to seedlings suitable for reforestation.
In general, it is the ability of solids to undergo permanent deformation without fracture. More specifically, it is a natural or artificially induced property of a piece of wood that makes it capable of keeping its shape after bending.
Substance incorporated into an adhesive to increase its elasticity and spreadability. Its inclusion can result in a reduction in viscosity, a lowering of the second-order transition temperature, and a decrease in the modulus of elasticity of the solidified adhesive.
In the structural use of plywood, the constraint condition in which the four sides of the panel are supported or interlocked.
Flat, rigid metal element part of the hot press. When heated by hot water, steam, or diathermic oil, it enables the transmission of heat and pressure necessary for the gluing and production of plywood and other panels and wood-based products.
Kiln in which the wood to be dried is placed between two heated metal plates.
Particleboard obtained by hot pressing the mat of particles mixed with a previously introduced binder. The pressure is perpendicular to the faces of the panel.
Face featuring elements with a pleasing overall appearance. There is no requirement for the grain of the various components to match the joints. No sharp colour contrasts are permitted at component joints.