| Timber merchants sell most of their wood in | | | | sizes in millimetres! |
| standard pre-cut sizes. The standard lengths for | | | | The most common thicknesses for both sawn and |
| softwoods start at 1.8m and increase in multiples of | | | | planed softwood timber start at 12mm (1/2 in) and |
| 0.3m to a length of 3.9m, though both longer and | | | | go up to 100mm (4in). Intermediate sizes are 19mm, |
| shorter lengths can be obtained. With hardwoods the | | | | 25mm, 32mm, 38mm, 50mm, 63mm and 75mm, |
| situation is much more complicated and as it is likely | | | | though you may also find 16mm and 22mm |
| that a timber merchant will stock relatively few sizes, | | | | thicknesses for planed timber. |
| it is worth checking with him before deciding on what | | | | The common widths start at 25mm (lin) and go up in |
| lengths to buy. In very general terms, hardwoods | | | | 25mm steps to 225mm with just one fairly common |
| start at 1.8m in length, though shorter lengths are | | | | intermediate size (38mm) and a few less common |
| often available. | | | | ones (32mm, 112mm and 138mm, for example). |
| The standard widths and thicknesses available | | | | Not all thicknesses are available in all widths, and |
| depend on whether the timber is left rough sawn or | | | | some sizes are available only as planed timber or only |
| planed smooth. | | | | as sawn timber. Small sizes are generally available as |
| For softwood, two finishes are widely available: | | | | mouldings. |
| Sawn | | | | Where wood needs to be a specific size (for joists |
| The timber is cut to standard sizes in both width and | | | | or studs, for example) you can get regularised timber |
| thickness by large power saws. Sawn timber is sold | | | | which is exactly its stated size. |
| by its nominal size - as cut from the log. After drying, | | | | For most do-it-yourself work, you will be using a |
| timber shrinks slightly so the size of sawn timber | | | | limited range of sizes - typically 25mm by 50mm, |
| when it is bought is slightly less than its nominal size. | | | | 25mm by 100mm and 25mm by 150mm planed |
| Planed all round (PAR) | | | | softwood and 50mm by 100mm or 50mm by 200mm |
| This is sawn timber which has had all its sides | | | | sawn softwood and these should be readily available. |
| smoothed and made parallel by planing. A PAR size is | | | | The sizes of pine available for shelving generally stops |
| usually around 3 to 5mm less than the nominal sawn | | | | at 225mm (9in); for wider sizes you will have to go |
| size. | | | | to parana pine. |
| The sizes of timber available are based on the metric | | | | Hardwood is always sold as planed all round and the |
| equivalents of the original inch sizes. Many timber | | | | number of sizes available is likely to be more |
| merchants still talk and think in inches, and you may | | | | restricted: ramin comes in smaller sizes than red |
| even find nominal sizes quoted in inches with finished | | | | hardwood. |