Glossary of Timber Terms
Abbreviations and meanings of the timber terms used for finishing, treatment, grading, building and more.
| Term | Meaning | Abb. |
|---|---|---|
| Finishes | ||
| Rough Sawn | As it comes straight off the saw | R/S |
| Band Sawn | Vertical saw cut | B/S |
| Dressed Four Sides | Dressed smooth suitable for joinery | D4S |
| Plainer Gauged | Machined at high speed to a standard uniform size for the building market | P/G |
| Tongue & Groove | T&G | |
| Tongue & Groove V-Joint | T&G V-J | |
| End-Matched | E/M | |
| Pre-primed | Undercoat sealer (oil or water based) | P/P |
| Treatment | ||
| Untreated | Untreated | U/T |
| H1.2 | Boron treated for protection against borer | H1.2 |
| H3.2 | Exterior treated for exposure to weather but not in ground contact | H3.2 |
| H4 | Ground treated for ground contact | H4 |
| H5 | Treated for ground contact ground near fresh water or in soggy ground | H5 |
| H6 | Treated ground for near salt water | H6 |
| Grades | ||
| Dressing A | Knot and defect free | D.A |
| Dressing B Select | Small tight knots on all 4 faces. Will be able to cut some clear out of the board | D.B. Select |
| Dressing B | Tight knots with no restriction on the amount per board | D.B |
| Clears | Knot and defect free | CL |
| Clears 2 | Clean on 2 edges, 1 face and small tight knots on 1 face | CL2 |
| Dressing Grade | Tight knots that can be cracked with no restriction on the amount per board. Hairline cracks in board are possible | D/G |
| No.1 Farming | Knot size no bigger than 1/3 cross section of the board | No.1 |
| Boxing | Has spike knots, butterfly knots, loose knots and edge knots | BOX |
| Ordinary Building | Pinhole borer, cracked knots, hairline cracks in board, large knots | O.B. |
| Double Defect | Open defects on back and face of plywood | DD |
| Finger-Jointed | F/J | |
| Durability | ||
| Non Durable | 0-2 years | |
| Moderately Durable | 2-5 years | |
| Durable | 5-10 years | |
| Very Durable | 10+ years | |
| Defects | ||
| Pinhole | A hole usually not exceeding 2mm diameter. The insects that create these holes feed off the starch in the sap of the living trees and when the tree is felled, sap dries up and they die | |
| Gum Vein | A ribbon of gum produced in trees as a response to fire damage | |
| Shake | Splits in the structure of the wood caused by growth defects or shrinkage stress | |
| Check | A small crack running through the grain of a timber surface usually caused by being dried too quickly | |
| Dry | ||
| Moisture Content | The amount of moisture in timber (measured in a percentage) | MC |
| Kiln Dried | Has been dried in a kiln to approx 12-15% MC | K/D |
| Air Dried | Has been dried by natural air (usually undercover and strip-stacked) to anywhere between 15-15% MC | A/D |
| Green | Wet (ranging from 26-100%) | |
| Measurements | ||
| Lineal Metre | Running metre in .300 multiples | LM |
| Square Metre/Area | Length x width | m2 |
| Cube | Length x Width x Depth | m3 |
| Building | ||
| Purlin | Sits on top of trusses | |
| Truss | A triangular arrangement of structural members that reduces non-axial forces on the truss to a set of axial forces in the members | |
| Stud | One of a small series of small closely spaced wall framing members | |
| Dwang | Block in between studs | |
| Joist | One of a group of light, closely spaced beams used to support a floor deck or flat roof | |
| Bearer | Heavy section timber which supports joists | |
| Batten | A long thin piece of rectangular shaped material supporting roof tiles or covering joints between panelings | |
| Beam | A straight structural member that acts primarily to resist non axial loads | |
| Post | Upright supporting a structure | |
| Pile | A long slender piece of material driven into the ground to as a foundation | |
| Plinth | Triangular shaped timber for corner. | |
| Lintel | A beam that carries the load of a wall across a window or door opening | |
| Jamb | The vertical side of a door or window | |
| Gable | A roof consisting of two oppositely sloping planes that intersects at a level ridge | |
| Rafter | A framing member that runs up and down the slope of a steep roof | |
| Baluster | One of a series of short posts or pillars that make up a balustrade and support the rail at the top and stand on the base at the bottom | |
| Tread | The horizontal portion of a stair which a user places their foot on | |
| Riser | The vertical portion of a stair |