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.
Presence of two piths, each with its own system of growth rings, at one end of the round timber.
Annual ring consisting of two (or more) growth rings.
Applying adhesive to both surfaces of a joint.
Process involving the application of a final vacuum after the immersion phase. NOTE: a pressure of up to 300 kPa can be applied during the immersion phase. This process is sometimes referred to as a low-pressure double vacuum process.
Apparent chromatic difference as a result of the different light refraction of veneers when they are bookmatched. It occurs because the faces of the loose side and the tight side alternate in adjacent veneers reflecting the light in a different way.
Carpentry connection in which two flat wooden elements are connected to each other at an angle to the grain by means of a front and a rear notch and in which the load is transferred predominantly by compression.
Wood species Scientific name: Pseudotsuga menziesii (Mirb.) Franco. The name ‘Douglas fir’ is applied to wood from European reforestations. Origin: North America (coastal and mountainous regions towards the Pacific in Canada and the USA, from Oregon to California); cultivated in Europe.
Junction, normally at right angles, obtained by gluing two pieces that have been shaped with slanted edges, in other words, cut into a dovetail shape.
Cylindrical bar of wood or steel inserted into previously drilled holes to make a joint.
Joint in which wooden workpieces are united by dowels that cross the joint longitudinally or transversely.
Panels which, instead of nails or screws, use cylindrical wooden bars as connectors for joining togheter the wooden elements.
A connection between two or more elements joined together by dowel-type fasteners
Any tree lying on the ground that has been uprooted, stumped, or deliberately felled. For a collection of trees or logs, it can be referred to as “felled timber”.
Proposed rule generally made available for comment, evaluation, or approval.
An artefact intended to allow modest amounts of water to flow under a road.
Sanded timber on one or more surfaces
A joint in which the glue on the two surfaces has dried without setting due to inadequate pressure, too long assembly time, use of too viscous glue, etc.
Pre-treatment operation carried out, on impregnation-resistant woods, by drilling holes in order to achieve deeper and more uniform impregnant penetration.
Specialist worker in tractor driving.
Qualified worker assigned to drive quadrupeds.
Wood and bark cracks developing longitudinally resulting from a severe dry period.
Part of a winch on which a rope is wound. It consists of a central cylinder (core) bounded by flanges.
See “crystal”
Temperature measured by the dry thermometer of a psychrometer.
Conditions corresponding to service class 1 of EN 1995-1-1:2004, whereby the moisture content in the material corresponds to a temperature of 20°C and a relative humidity of the surrounding air over 65% for only a few weeks per year.
Fiberboard having moisture content lower than 20% at the forming stage. Note: The manufacturing of these panels takes advantage of the effect of heat and pressure with the addition of a synthetic adhesive.
Wood rot caused by the fungus Serpula lacrymans NOTE 1: In the German language, the literal translation ‘Trockenfäule’ indicates that there is no infestation caused by the fungus Serpula lacrymans. NOTE 2: In current language, the literal translation ‘pourriture sèche’ is not actually used in practice.
Outer part of round wood or log consisting of dead tissue.
Property of some adhesives to adhere to each other even though they seem completely dry to the touch.
Removal of dry branches.
Machinery used for drying wood. Depending on the types of equipment and modes of operation, there are: – cell dryers (Dutch chambers, hot-air and condensing chambers); – vacuum-pressure dryers; – electromagnetic wave dryers; – tunnel dryers (roller or mesh).
Condition under which the drying process takes place. Air velocity, drying temperature and psychrometric difference (or relative humidity or equilibrium moisture) are to be specified for characterization in accordance with the type of dryer control system in use.
Defects that develop during the drying process, resulting from the application of an unsuitable drying regime, inadequate control of the process or malfunction of the equipment.
See “damage during drying”.
Phase of the drying process during which moisture is extracted from the wood. It is usually divided into at least two parts, depending on whether the average moisture content of the wood is above or below the saturation point.
Ratio of the actual average moisture content of the timber being dried to the actual equilibrium moisture content in the dryer.
Ratio of decrease in average humidity to the time in which it occurred (usually per hour or day).
The regime of a drying process in which drying conditions for different species are determined by time or average moisture content.
It denotes a risk management activity aimed at minimizing the risk of marketing illegally sourced timber or wood products containing illegally sourced timber. The three key elements of the due diligence system are information, assessment and risk reduction.
Square timber (mostly beams or sawn timber) with irregular edges and the presence of bevels or rounding.
Resistant wooden packing material used to protect or support a commodity during transport, yet does not remain associated with the commodity.
Estimation of the durability of a bonding under the expected operating conditions of the product.
Wood with natural resistance to attack by xylophagous organisms.
The transformation process of sapwood cells into heartwood cells. It affects the transition zone between the two portions and in particular the innermost band of sapwood cells (the one closest to the pith).
Type of oven for burning sawdust and other sawing residues.
Individual hearing protection device for excessive noise.
Individual ear protection device against excessive noise.
Bark formed during the early stages of the season.
Portion of the growth ring that forms during the early part of the growing season. It generally consists of less dense and mechanically weaker wood than wood formed during the late growing season.
Heavy construction machine (dozer, track and wheel front-end loader, excavator, bulldozer, grader) specialized for digging or moving material.
Wood species Scientific name: Agathis dammara (A. B. Lamb.) L. C. Rich. Origin: Asia
Wood species Scientific name: numerous species of the genus Diospyros (D. ebenum and D. celebica). Origin: Tropical zone of East Asia and the Pacific Islands.
Wood species Scientific name: Juniperus virginiana L. Origin: South-eastern regions of the United States.
Wood species Scientific name: Tsuga canadensis Origin: Eastern North America
Wood species Scientific name: Juniperus virginiana L. Origin: South-eastern regions of the United States.
Wood species Scientific name: Picea glauca Voss Origin: Eastern regions of Canada and north-eastern United States.
Pith that, in the cross section of round timber, appears offset from the geometric center.
Veneer with a straight grain effect, obtained by a rotary cut slightly angled to the radial of the half-round log.
Veneer produced as a result of eccentric clamping of the log in the rotary lathe.
Surface defined by the height and perimeter of a sawn timber, a semi-finished product or a wood-based panel. In the case of sawn timber, the French term ‘Chant’ is used when the piece is planed or otherwise further processed.
A joint between two pieces placed and normally glued edge to edge.
Knot visible on the edge of a sawn timber.
Application of a surface treatment or coating (e.g., sealant, paint) to the edges of a semi-finished product (usually a wood-based panel) aimed at reducing its moisture absorption. All edges of panels used in the outdoor environment should be sealed. This operation is most easily performed on stacked panels
Sawn timber sorting equipment, in which the timber is led by rollers to a measuring point. Subsequently, the various pieces are automatically directed to the appropriate place according to their length.
In plywood, wedge-shaped separation of an inner ply caused by the breaking of the edge of a sheet that occurred before or during pressing.
Stacking accomplished by arranging the pieces horizontally but placing them on the edges so that the faces are vertical.
Alignment condition of multiple points on the edge of a panel or semi-finished product. It is usually measured over one meter of edge length.
Defect in a plywood in which the edges of an inner foil have split or ruined during panel production resulting in clearly visible discontinuities at the edges of the panel.
Sawing machine used to divide the width of boards and to cut sawn timber into sharp arris by removing the wanes.
Machinery used for edging semi-finished products.
A device used to cut flush and even the edges or contours of a semi-finished wooden product, removing the so-called trim.
Operational phase consisting of the application, usually by gluing, of thin strips of solid wood, strips of foil, paper or plastic materials as a decorative finish to the edges of a semi-finished product.
Acts of the Commission and the Council of the European Union. They may be adopted to pronounce judgment or to impose sanctions on persons, business entities or states that have infringed EU rules. Decisions are binding on those to whom they are addressed and take effect upon notification.
Portion of the cross-section of a wooden element that is presumed to be in good condition to withstand various stresses.
This is the representative cross-section of a critical zone. Defects, alterations, damage and other features occurring in the critical zone and affecting its strength are attributed to the critical cross-section.
In preservative efficacy determination methods, it is the range between the preservative concentration that allows the attack of a given fungus or survival of a given insect and the nearest higher concentration that prevents the attack of the fungus or insect under investigation.
Maximum stress that a material is capable of supporting without incurring any residual deformation upon release of tension.
A macromolecular material that, at room temperature, is capable of substantially recovering its size and shape after the removal of a force that resulted in its deformation.
Ability of a material to obstruct the flow of electric current between two conductors with different potential.
Estimation of the wood moisture obtained through the use of a hygrometer whose operation is based on the relationship between the humidity of the material and an electric field induced by the instrument.