Glossary

A ribbon-like arrangement of cells, usually oriented in the radial direction.

A chamber into which wet steam (not more than 100°C) is injected for several hours to recondition timber.

A high temperature/high relative humidity (100%) treatment applied after drying to restore the shape of collapsed or distorted wood.

An instrument that continuously records dry- and wet-bulb temperatures of circulated air in a dryer or kiln and regulates these conditions by activating automatic heat and humidification systems.

In kiln or veneer drying, a process whereby dried material found to have a moisture content level higher than desired is returned to the dryer for additional drying.

In timber drying this term is used to indicate high resistance to moisture loss during drying.

The National Forest Policy Statement defines regrowth forest as native forest containing a substantial proportion of trees that are in the younger growth phase and are actively growing in height and diameter. Regrowth forests may contain scattered individuals or small occurrences of ecologically mature or old growth trees.

At a given temperature, this is the amount of moisture in air as a percentage of the maximum moisture carrying capacity of the air, i.e. the water vapour pressure as a percentage of the saturated water vapour pressure.

A class of amorphous vegetable substances secreted by certain plants or trees.

An adhesive made from resorcinol resin and formaldehyde.

The surface left exposed when one board is fastened over another; the edge of the upper set slightly back from the edge of the lower.

The persistent echoing of sound within an enclosure after the original source of the sound has stopped, due to repeated reflection between the enclosing surfaces

A striped figure produced by cutting timber that has an interlocked grain. Also called striped figure.

The highest part of the roof at the meeting of the upper ends of the common rafters.

A beam located at the highest part of the roof to support the upper ends of the common rafters

To cut along the grain.

Small timbers fixed to the top of rafters to which the roofing material is secured.

Markings in the form of a twisted rope.

Veneer cut in a lathe which rotates a log chucked in the centre against a knife. This method of peeling is used to produce decorative veneers and is a common method of manufacturing veneers for plywood.

Surface condition of wood as it leaves the saw, i.e. not dressed or final sawn.

Timber used in the original round form, such as in poles, posts or bridge beams.

To cut out by gouging.

A representative piece of timber of a known moisture content that is placed in a stack, or a predryer or kiln charge, so that it may be removed for comparative examination, weighing, or testing during the drying process.

The fluid in green wood that contains nutrients and other chemicals in solution.

A discoloration in the sapwood caused by the growth of fungi. Sapstain is often blue but can also be red, purple and other colours.

Outer layers of wood which, in a growing tree, contain living cells and reserve materials such as starch. Under most conditions the sapwood is paler in colour and more susceptible to decay than heartwood.

Veneer produced by sawing

Timber finished to size with a saw.

A joint made by bonding two matching beveled ends or edges.

To mark for an irregular cut.

Timber that has been dried so that the maximum moisture content anywhere in the piece does not exceed 15%.

Drying timber to a moisture content appropriate to the conditions and purposes for which it is to be used.

Stresses in timber caused by variation in shrinkage as it dries.

Permanent deformation in wood that occurs during drying when the tensile and compressive stress exceeds its elastic limit. Set prevents normal shrinkage of the timber and can lead to more obvious defects such as casehardening.  

Occurs during compression, which tends to give the wood a smaller than normal dimension after drying. Compression set is usually found in the inner layers of wood during the later stages of drying, but sometimes occurs in the outer layers after extended conditioning or rewetting. Tension - Set that occurs during tension, which tends to increase the dimensions of the wood after drying. Tension set usually occurs in the outer layers of wood during drying.  

Separation or breakage of the wood fibres caused by stresses in the standing tree or by felling and handling of the log. It is not caused by shrinkage during drying.

A condition of stress or strain where parallel planes slide relative to each other.

A condition of stress or strain where parallel planes slide relative to each other.

A selection of wall designed to resist lateral forces acting in, or parallel to, the plane of the wall

A shaped connector made of sheet metal and perforated so that nails can be driven through.

The reduction in dimension or volume which takes place in timber when the moisture content is reduced below fibre saturation point, expressed as a percentage of the original dimensions or volume. Linear shrinkage occurs in three directions radial, tangential and longitudinal.

The bottom member of a door or window frame. It is usually angled to shed water.

The structural member forming the bottom of a rough opening for a door or window.

A monoslope (single pitched) roof without a ridge or peak, providing the main roof or part of a roof

Veneer that is sliced off a log or flitch with a knife.

A unit of timber. Synonymous with pack.

In timber and other wood products, the ratio of deviation of the grain from the long axis of a piece to the distance along the edge that this deviation occurs.  

A general term for timber of trees classified botanically as Gymnosperm. Commercial timbers of this group are nearly all conifers. The term has no reference to the relative hardness of the wood.

Segregation of sawn wood items into groups that have similar characteristics, such as thickness, species, grades, and grain patterns, and into classes for stacking or racking, such as width and length.

A knot that is solid across its face, at least as hard as the surrounding wood, and shows no indication of decay.