Wood in Joinery
Carpentry is the term applied to making structures out of wood that are very often not seen.
Joinery on the other hand is the term used to describe working wood to provide the visible parts of our built environment. Examples are doors, architraves, skirting boards, staircases, windows as well as flooring and some furniture. The need for high precision and finish has resulted in the development of very sophisticated machinery. Shopfitting can give many examples of imaginative and innovative design and manufacture.
It follows that the raw materials used must have minimal defects and good working properties. Tight control of moisture content at all stages ensures stability in service.
Softwoods and hardwoods can be used, but MDF board has won favour for skirtings, architraves and staircases owing to its stability and availability in long lengths. It can also be supplied pre-finished which can save time and labour on site.
All softwoods can theoretically be used, but Scots Pine (European Redwood) is the favourite since it machines and finishes exceptionally well. Higher grades/qualities are used so as to minimise the number of knots. Modern technology has developed finger jointed material that is defect free. This can further be laminated into larger sections and dimension stock which can improve stability and reduce waste.
Exterior joinery (windows and doors) must also be durable, and resist insects and fungi. This can be achieved either by using a naturally durable species, or by impregnation with preservative chemicals. To achieve the performance and service life needed, factory pre-finishing gives superior results.
Modern technology has produced modified wood, either chemically or heat treated, that is more durable and stable than natural wood.
Modern demands for weather tightness, draught proofing and security has resulted in machinery that can produce sections of extraordinary complexity with extreme precision.
All hardwoods can be used for internal joinery although some species are especially popular.
Contributor: Gervais Sawyer FIMMM