Glossary - S

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.

see beam grid

A subdivion of a genus in the classification of plants. Species of plants are distinguished by the characteristics of fruits,flowers, leaves, bark and wood.

The ratio of the density of wood to the density of water at 4 C. Specific gravity of wood is usually based on green volume and oven-dry weight, in which case it is known as basic specific gravity. See also basic density.

A form of cross grain in timber in which the fibres take a spiral course about the trunk of a tree instead of the normal vertical course. The spiral may extend in a right handed or left-handed direction around the tree trunk.  

To join the ends of timber elements together.

A defect that occurs when tensile stresses cause the wood fibres to separate and form cracks. Splits are cracks that extend through a piece.

A longitudinal curvature of the edge of a piece of timber, not affecting the face.

Support point or origin.

Spruce-Pine-Fir, or SPF, is the generic name for a variety of softwood species, even-grained and yellowish-white in colour, imported from North America and used in housing construction frames.

The gaseous form of water at or above the boiling point. Saturated - Steam at 100°C and atmospheric pressure.  

A treatment sometimes carried out before commencing a drying schedule. The timber is subjected to live steam. See also reconditioning.

Indentation or compression of the timber or other wood product by the rack stick (used for drying) when the load above is too great for the bearing area. Sticker marks or sticker stain also refers to light areas under the rack stick that form as the rest of the timber darkens.

All elements used to support or stiffen the slender webs of box and I-shaped beams and to enhance compressive capability of webs at support points or points of high transverse loads.

A long bolt through laminated timber that holds the laminations together.

Timber in which the fibres run parallel to the axis of a piece.

The ability of a member to sustain stress without failure.

Species of timber are classified into groups according to mechanical properties of the wood of that species and AS 2878, Timbers - Classification into Strength Group. There are seven strength groups for unseasoned timber (S1 the strongest to S7 the weakest) and eight for seasoned timber (SD 1 the strongest to SD 8 the weakest).

1) A beam that joins the top of columns and supports the cross members in floors and ceilings. 2) An inclined member that supports the treads of a stair. 3) A deck element in timber bridges that supports transverse deck planks and runs parallel to the beam span  

Timber to be used in construction where its strength is the controlling element in its selection and use.

A structural timber resisting compressive forces along the grain.

One of a series of vertical framing timbers used as a supporting element in a wall or partition.

The heat in steam in excess of the amount of heat in saturated steam at a given pressure.