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.
Woody biomass in the forest consisting of trees that had already died before being felled.
See “Xestobium rufovillosum”.
Wood that has undergone any process involving the removal of bark Note: debarked wood is not necessarily bark-free wood.
Machine used for debarking round timber. Depending on the models and operating methods, there are: – drum debarkers (used for pulp logs, they cause mutual friction between the pieces inserted in a large, slightly inclined rotating metal cylinder to aid the movement of the material being processed); – chain debarkers (in which bark is removed by short pieces of chain extending by centrifugal force from a rotating container); – rotor or ring debarking machines (in which a set of knives – scoring and ripping knives – installed on the periphery of a rotating ring remove bark as the workpiece, secured by special feed rollers, passes through the ring); – milling-head debarkers (in which a rotating head equipped with surface protuberances strips bark from the workpiece as it moves forward by rotating on a support system).
Processing stage involving the removal of the bark of a woody stem.
Large rotating cylinder within which trunks or logs are debarked by mutual friction or on special attachments such as chains, rough surfaces, etc.
Tool for practicing manual debarking.
Remove the bark from a whole stem or round timber. The operation can be carried out more or less completely.
Parquet consisting of strips of equal length, whose joints are arranged on crosspieces placed perpendicular to the direction of the strips.
Wood materials utilized for lining parts of bridges and other structures which are subject to vehicular or pedestrian traffic.
Declaration by a supplier, on his sole responsibility, that a product or service conforms to a standard. Generally, the authority to make this declaration is subject to a check by the party itself (e.g. verification of the supplier’s quality system).
The CPR Regulation is legislation that regulates the production and marketing of construction products by requiring economic operators, i.e., manufacturers, agents, importers, and distributors, to comply with a number of obligations to ensure the quality and safety of products. These obligations are: -The Declaration of Performance (DoP), which is the document that certifies the performance of the product in relation to the essential requirements established by the Regulation. -CE marking, which is the symbol indicating that the product complies with the essential requirements of the Regulation and the DoP. The CE marking must be affixed to the product, its packaging or accompanying document and must contain the information required by Articles 8 and 9 of the CPR. -The preservation of the technical documentation, which is the body of data and evidence that supports the DoP and CE marking. The technical documentation must be kept by the manufacturer for 10 years after the product is placed on the market. -Product identification, which is the process of recognizing the product by a number or mark. The manufacturer must indicate on the product, its packaging or accompanying document its name, registered trade name (or trademark) and address where it can be contacted. -Safety information, which is the instructions or warnings that accompany the product to ensure safe and appropriate use. The manufacturer must ensure that the product is accompanied by information regarding the safety of the product in accordance with the requirements of the member state in which it places the product. -Corrective actions, which are the measures that must be taken if the product does not comply with the DoP or Regulation 305/2011.
A improper term that would be used to refer to a manufacturer’s declaration of the conformity of its products, without the intervention of an independent third party. It is improperly used in place of the term “declaration of conformity.” The term is incorrect because the word “Certification” in the specific meaning always indicates that the verification is carried out with the intervention of an independent third party.
Decrease in pressure upon a particle mat prepared during hot pressing. Its purpose is to release the vapor pressure trapped within the mat or to stop further compaction of the mat.
Layered panel composed by consolidation of resin-impregnated paper sheets of which the surface one has a decorative pattern or appearance.
Knot resulting from an already dry branch in the standing plant.
Blue stain that cannot be removed by simple planing. Conventionally it is called “deep blue” if it exceeds 2 mm in depth.
Treatment that affects both the outer and deeper layers of wood.
Large ploughshare-moldboard, suitable for deep soil tillage with soil turning over.
Irregularities affecting a wood assortment, semi-finished or finished product that simultaneously compromise its future use and commercial value. In this context, “wood defects” (irregularities in structure compared to a situation considered normal) and “processing defects” can be further distinguished. Defects considered unacceptable for a given finished product must be eliminated during its production process. In the terminology referencing quality, defect means the failure to meet requirements in relation to the intended use. In this sense, the definition refers to the deviation or absence of one or more quality characteristics from the requirements necessary for the intended use.
A method of qualifying timber (logs, square timber, sawn timber, etc.) based on the examination of its surface and exclusively taking into account the nature, importance and distribution of certain localised defects.
Not conforming to a request or technical specification.
Presence of chipped, damaged, frayed or marked edges.
Mechanical, chemical, or thermo-mechanical action through which chips, sawdust, or culls can be reduced into fiber bundles.
Machinery used for defibering wood.
Deformation value of the midline of a sample tested under the action of a static (uniform or concentrated) or dynamic load in relation to a flat reference surface. It is measured at the midpoint between the two ends of the wood sample.
Removal of the tree component in a forest land-use area.
Controlled drying process in which warm, moist air circulating inside the cell is dehumidified by condensing the vapor using a dehumidification device (usually an electric heat pump).
Separation of the layers of wood elements glued together due to both lack or loss of adhesion at the interface and loss of cohesion within the adhesive layer or one of the adhesives.
Detachment of one of the layers of a plywood panel, core plywood, and other panel.
It is the sum of the delaminated glue line lengths on both end-grain surfaces of a workpiece sample.
The removal by chemical treatment of a part or the entire lignin component of wood.
A machine that performs the limbing stage by cutting branches from the stem.
Processing stage during which branches are cut from the tree, normally after it has been felled. Sometimes topping is also considered to be part of this stage.
Treatment that involves the wood passing through a tunnel in which the preservative is sprayed or flooded over it.
Set of scientific methods used to determine the time space during which a tree was felled, transported, processed and used for construction.
1) In a broad sense, the science concerned with the temporal location of the annual growth rings of tree plants. Dendrochronology includes as well investigations of the wooden structures to which the dated rings belong, as well as extrapolations and applications in the environmental and historical fields. 2) In a strict sense, the term can also refer to subdisciplines of Dendrochronology, such as Dendroarchaeology.
Dendroecology subdiscipline that uses annular series data to reconstruct and study the climate of the present and past.
Dendrochronology subdiscipline which uses all the subdisciplines of Dendrochronology that can provide information in the ecological and environmental fields. It deals particularly with climate (dendroclimatology), water flows (dendroidrology), geomorphic processes (dendrogeomorphology), glacial movements (dendroglaciology), snow, tectonic processes, fire, stand dynamics, anthropogenic influences, chemistry (heavy metals: dendrochemistry), isotopes, etc.
Graphical representation of the density trend measured along a ray of a wood specimen.
See “density”.
Ratio of the mass of wood or a semi-finished product to its volume measured generally under the same moisture conditions. Density mass is generally expressed in kg/m3. In English-speaking countries it is also expressed in pounds per cubic foot. Since, in the case of wood, mass and volume change as the moisture content of the material varies, some notable moisture values have been defined to which the measurement of density should be referred; these are: – the fresh state (wood moisture above the saturation point of the cell walls); – the commercial moisture (equal to about 15 percent); – the normal moisture (by convention equal to the equilibrium moisture attained by a specimen exposed to 20±2 °C and 65±5 % until a constant mass value is reached. In solid wood, it is about 12%, in many other wood products it is slightly lower; – the anhydrous state (attainable from a sample exposed in a ventilated stove at a temperature of 103±2 °C until a constant mass value is achieved).
Variation in density detectable between the face and the middle of the thickness of a recomposed panel.
Round timber felled and stripped of all the sapwood (usually to prevent biodeterioration).
Formal, documented, comprehensive and systematic review of what has been designed, to assess both the requirements considered in the design and its suitability to fulfill and identify problems and prepare solutions. Design review in itself is not sufficient to ensure adequate design. A design review can be carried out at any stage of the design. Design validity includes aspects such as fitness for purpose, feasibility, ease of manufacture, measurement and maintenance, performance, reliability, safety, ecology, and cost (on a time scale and life cycle basis). Design review requires qualified personnel, including all functions relevant to quality.
Process whereby liquids or gases depart from a solid; it is the opposite of adsorption. The term “sorption behavior” includes both.
An assembly element with a rectangular cross-section, used to join two flooring elements supplied with grooves only.
See “fungi imperfecti”.
A length of a curved element which is measured on the outermost side of the lamination presenting the largest radius.
Temperature at which steam begins to settle in liquid form. It applies specifically to water in the atmosphere.
Process consisting of identifying the current conditions of a structure and determining the causes of any changes.
Distance between two parallel lines tangent to the trunk (or stem).
Diameter of the trunk of a standing tree which, by convention, is measured at about 1.30 meters in height from the ground.
Diameter at ground level. It may be specified when selling standing timber, in opposition to the common usage of measuring ” at breast height “.
Diameter measured at the point where the stump and stem (collar) join and where trees are cut and sometimes measured. If the terrain is sloping, the stump level is taken upstream.
Diametric increase in the stem of a tree plant.
Automatic reduction, by means of special mechanisms, of the knife angle of a veneer peeling lathe as the diameter of the log is reduced with the proceeding of the rotary cutting.
Deformation caused by the change, during the drying process, of the cross-sectional area of a squared timber that takes on a rhomboidal shape. It is caused by the difference between tangential and radial shrinkage.
The property of a material measured as the ratio of the capacitance of a given configuration of electrodes with the material acting as a dielectric placed between them to the capacitance of the same configuration of electrodes in which the vacuum acts as a dielectric.
A measure of the energy per unit volume that will be converted to heat in a nonconducting material which is subject to an external electric field that varies with a given amplitude and frequency.
Any material that does not conduct electricity. It is also called, more simply, “dielectric.”
Single rows of apotracheal parenchyma or cells irregularly distributed between fibers in cross section.
Apotracheal parenchyma cells that tend to cluster, in cross section, in short tangential lines from ray to ray. It is also called “diffuse-zonate parenchyma”. Note: This type is also often reticulate.
Characteristic feature of wood of some broadleaf trees in which the vessel elements (or pores) in cross section appear to be of uniform size and distribution within each growth ring or only slightly and gradually decreasing toward the outer limit of the ring.
Spontaneous process by which physical states or concentrations tend to equalize as in the case of differences in temperature, gas pressure, and solutions at different concentrations. The term is also used to refer to the penetration of an impregnating agent into wood.
Process in which a salt impregnant in the form of a paste or concentrated solution is applied to undried wood. The impregnant diffuses inside the wood by osmosis.
Treatment in which the water-based wood preservative is applied to the surface of green wood in a paste or concentrated solution. It is gradually transferred into the wet wood under the force of the concentration gradient.
Additive that reduces the effect or concentration of a mixture or solution.
Lot of sawn timber having a specific size in relation to future use.
Situation in which one or more dimensions (length, width and thickness) exceed tolerances on nominal values.
Degree of maintenance of its own dimensions of a semi-finished product when exposed to extreme conditions of temperature and humidity.
Treatment aimed at reducing shrinkage and swelling of wood caused by changes in its moisture content as temperature and relative air humidity change.
Treatment during which the timber is immersed in a preservative solution for periods of approximately 10 s to 10 min.
Growth ring that is not present around the entire stem.
Removal of an infection from wood.
Removal of an infestation from wood.
Cells of the axial or radial parenchyma, partially disjunct during the differentiation process. The contact is maintained by tubular processes.
Tracheid partially detached laterally from another one during differentiation. Contact is maintained by tubular processes.
Pallets consisting of wooden elements of moderate thickness, made to be used only once. In practice, disposable pallets are often sorted or repaired to be reused a limited number of rotations.
Geographical and altitudinal area where a species or subspecific entity has been introduced and spread by humans.
Artificial ditch that can be set up upstream or exceptionally even downstream of roads to collect surface runoff water.
1) Cross-cutting of the end parts of round logs in order to bring them to the desired length and to eliminate defects. In particular, to remove butt trimming made to facilitate extraction. 2) Similar cross-cutting of sawn timber, occasionally still provisionally leaving a length in excess of the desired length, which constitutes a heading margin. 3) Cull resulting from the previous operations, including cuttings, pieces cut from the ends of boards to bring them to the precise desired length.
Mechanism (roller) that, in a roller glue spreader, operates in close connection with an applicator roller system and with a controlled gap between them.
Curved, pointed steel projection for holding a log fixed on a saw carriage (upper and lower hook) or on a plate of an endless chain log lifter.
Wood species Scientific name: Cornus sp.p. (Cornus mas L. o Cornus florida) Origin: USA
Locally sourced wood or timber.
Period in which the growth of the tree is temporarily suspended (for example during the winter or due to drought).
See “dote”.
Early stage of rot that can be observed in wood of Beech, Maple, Hornbeam, and Alder. The wood shows irregular grayish-white areas bordered by black lines composed of mycelium.
Altered red heart in Beech with a star shape. It is noticeable at the ends of the trunks.
The covering of a core plywood consisting of two sheets of peeled or sliced veneer overlapped and glued to each other with orthogonal grain direction and then applied to each face of the core. The outer layer generally shows perpendicular grain direction to that of the laths or lamellae of the core.
Treatment by prolonged immersion of wood, in successive stages, in different salt solutions.