Timber & Wood Glossary Of Terms
The woodworking world and timber industry have an entire codex of vocabulary and technical terms that aren’t always self-explanatory.
This glossary aims to help our visitors and clients understand the terms W. L. W West & Sons use for specs, planning and manufacturing. If we’ve missed any out, let us know!
Wood Words and Timber Glossary
| 1st | First Quality |
| 1/2 | A mix of first and second-quality timber. This can contain sapwood, sound knots, cross grain, or natural discolouration/streaking. |
| 1/S/E | One square edge, one waney edge. |
| 1+2 white | This term is used for the general description of Maple: white on one side, with slight discolouration on the reverse. |
| Architrave | A main beam resting across the tops of columns. |
| AD | Air Drying (or air-dried) |
| Back | Top rail of a timber gate. |
| Billet Sawn | Growth ring 45-90° to board face. Heart-split. |
| BM | Board Measure, the measure of the surface area multiplied by the thickness to give volume. |
| Bow | When the centre of a board is raised higher than the ends when laying on a flat surface. |
| Boule | French term for a Through & Through log, used in UK timber trade. |
| Brace | Strengthening rail built diagonally across a timber gate. |
| Brown Oak | Quercus Robur with fistulina fungus |
| Butt-jointed | When two pieces of material are joined by simply placing their ends together without any special shaping. |
| Case Hardening | Tension-set/ Compression-set. |
| Cats paw | Epicormic growths (shoots growing from a previously dormant bud on the trunk or a limb of a tree), also known as pippy knots. |
| Character | The overall look and feel that timber displays, typically said of Oak when the timber is not plain but features knots and other characteristics. |
| Check | A fissure that does not penetrate timber from one surface to the other. |
| Cladding | A building’s outer layer of either horizontal or vertical material meant to improve insulation and weather resistance. Can also feature in building interiors for stylistic purposes. |
| CND | Colour No Defect. Colouration in the timber is not considered and issue and is part of that species character. |
| Coppicing | A forestry practice that involves cutting back the stumps of young Hazel, Ash or Chestnut trees, which quickly regrow. This practice is used thatching and fence-making. |
| CTS | Cut to Size (to the nominal sizes required). |
| Cupping | A board in tension on one face. |
| Dead Knots | Evidence of ingrown bark – unstable. |
| Defect | An outdated term used to refer to knots and marks in timber, which are far from undesirable in many projects. We prefer to use `feature’ or `character’! |
| DM | Decimetre – square area of a board. |
| FAS | First & Seconds (clean one face) |
| FIN | Finish size |
| Fire Resistance | Although timber burns, it does not change form or suffer rapid strength deterioration when exposed to extreme heat. Char itself in fact acts as insulation, delaying further damage caused by fire. |
| FE | Feather Edged |
| FS | Fresh Sawn timber, also known as Green. Timber at this stage is still soft and moist. |
| FSC | Forest Stewardship Council |
| FOM | Free on motor. This term indicates the status of a product loaded safely onto the customer’s vehicle, but deemed ex-yard (ie: no longer on-site). |
| FSP | Fibre Saturation Point |
| Grain | Second only to colour in cosmetic importance, the pattern of grain is determined by the way a tree grows, which differs for all species. |
| Half a Gnats | 50% of a Gnats (see Gnats). |
| Half-lapped | Where two pieces of stock, typically of the same thickness, have half of the material removed so that the two boards fit together with no added thickness at the joint. |
| Hardwood | Timber from dicot (broadleaved) trees, such as Oak, Ash or Beech. Opposite of softwood. |
| Head | The second vertical from which a gate hangs (see hurr). |
| Heartwood | The inner rings of the log that no longer conduct sap. |
| Heart Shake | A separation between adjacent layers of fibre, radial and due to shrinkage through seasoning or old age. |
| Hurr | The main vertical of the gate from which a gate hangs. |
| Joinery | The craft (and art) of assembling timber components together for projects more complex than beams, shakes or panels. The resulting products include flooring, doors, windows and furniture making. |
| KD | Kiln dried timber. |
| Gnats | A very small measure (northern term). |
| Live Knots | Absence of ingrown bark – stable. |
| M/C | Moisture Content |
| Merchantable | Can include knots and face checks, but constructionally sound. |
| Moulding | Done using shaped metal profiles and sometimes called architectural joinery, moulding is part of the finishing process for the interior of a property. W. L. West & Sons Ltd make their own profiles for bespoke project and used this expertise to work on the mouldings of HMS Warrior. |
| NHLA | North American Hardwood Lumber Association |
| NOM | Nominal size |
| P/2/S | This refers to the board being planed on two faces. |
| PAR | Planed on all four faces (from the nominal sizes). |
| PEFC | Programme for the Endorsement of Forest Certification |
| `PTG | Planed, Tongue and Groove |
| PTGV | Planed, Tongue and Groove and `V’ |
| Prime | Clear, plain, knot-free timber typically prized by joiners and woodworkers. |
| Proforma | Payment prior to order being actioned. |
| Quarter Boards/ Quarter Sawn | These boards are radially cut which expose the medullary rays. It is rare for sawmillers to cut logs using this method, as it increases both waste and cost to mill, making the overall price increase substantially. |
| Ring Shake | Separation of one annual growth ring from another |
| Riven | Sawn on all four sides. |
| S4S | When shakes are hand-split instead of machine sawn. |
| Sapwood | The outer rings of the log. This can be very visible in some species (eg: Oak and Yew) and almost visibly non-existent in others (eg: Ash and Sycamore). |
| Scotia | A concave moulding, especially at the base of a column. |
| SE | Square Edges |
| Shake | Sometimes used interchangeably with the term `shingles’, oak shakes are hand-split timber tiles used for external timber cladding, particularly suited to churches due to their strength and durability. |
| Smidgeon | Another small measuring unit, similar to Knats above (southern term). |
| Softwood | Timber from coniferous or evergreen trees, typically used as building materials but not for their cosmetic value. |
| 1SE | One square edge, one waney edge. |
| Spleats | The remaining cross rails of a timber gate (see head, hurr, brace and back) |
| Spp | Species |
| Spring | Board laid flat but curved. |
| Shrinkage | The loss/evaporation of moisture from timber as it dries. Also known as moisture movement. |
| Star Shake | Excessive cross-sectional drying in logs, emanating from the heart, small and multiple cracks spread in the shape of a star. |
| STM | Sufficient timber to make the order |
| Tangential Boards | These are boards produced from the outside of the log. |
| Tannic Acid | Some timber contains tannin, Generally Oak & Chestnut which is corrosive to ferrous metals and leaves a blue stain on the timber when in contact with these metals. This, however, actually makes the timber even more durable. |
| Texture | How smooth the grain is,judged by running a fingernail across. |
| Tie Beam | A main beam resting across the tops of columns. |
| Tongue and Groove | When boards are joined by means of interlocking ridges and hollows down their sides. |
| T/T | Through and Through – A log sawmilled into plank and left with the bark edges (Waney Edged). |
| Twist | Propeller shaped board |
| Waney/Bevelled | The sloped-off shape on the two long longedges of log sawn timber (instead of square). |
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Weather-board |
A form of external cladding designed to overlap (unlike flush cladding). Particularly effective in damp or maritime climates where there is a risk from high salt-content spray. This can have a 1/S/E or square edge, usually fresh sawn if external cladding. |
| WE | Waney Edged – as T/T above. |
| WRC | Western Red Cedar |
Other useful terms may include:
Home decoration; cutting tools; sign wall; art wood; wood letters; word cutout; wood products; word wall; living tree; unfinished wood; board feet; forest land.
W. L. West & Sons Ltd is a timber merchant and sawmill business with 150 years of experience. We provide a wide range of air-dried oak and kiln-dried oak timber products and supplies. We also build and install custom projects for our customers.
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For entirely finished products, timber supplies or woodworking tools, have a look at our Retail Shop (which is temporarily closed for lockdown but will re-open in due course).
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