1. Making
1.1. Sawing
1.1.1. Timber is cut to required section by circular saw at a sawmill
1.1.1.1. Three types
1.1.1.1.1. Radial sawing (rift or quater sawing)
1.1.1.1.2. Tangential sawing
1.1.1.1.3. Slab sawing
1.2. Planing
1.2.1. If timber needs to have a smooth finish it can be planed
1.3. Seasoning
1.3.1. Describes the changes in timber from the time a tree is cut down to its use the construction of a building
1.3.2. The aim is to reduce the amount of moisture in the wood to an equilibrium with the moisture in the atmosphere
1.4. Preservation
1.4.1. Types
1.4.1.1. Treatments to resist attack by rot fungus and wood-eating insects
1.4.1.2. Treatments such as a paint, polish or varnish to protect it from moisture and pollution
1.4.2. Methods
1.4.2.1. Pressure impregnation
1.4.2.1.1. You put the timber in a kiln or other container a vacuum inside by pumping out the air
1.4.2.2. Steeping or immersion
1.4.2.2.1. You put the tomver in a tank filled with preservative
1.5. Stress grading
1.5.1. Structural timber must be stress-graded to give it stress-grade - standart strenght value which an engineer use to design calculations
1.5.2. Types of strenght-checking
1.5.2.1. Mechanically
1.5.2.1.1. Checked by machine
1.5.2.2. Visually
1.5.2.2.1. Checked by inspector
2. Joining
2.1. Timver can be shaped to koin pieces which lock together firmly
2.2. Types
2.2.1. Butt joint
2.2.1.1. A butt joint is not shaped and two pieces are only joined by glue
2.2.2. Dovetail joint
2.2.2.1. Joined pieces at right angles
2.2.3. Finger joint
2.2.3.1. Machined joint that joins two pieces end to end
2.2.4. Grooved joint
2.2.4.1. One piece fits into a groove on the edge of the other piece
2.2.5. Housing
2.2.5.1. At right angles in the middle of their lenght
2.2.6. Lapped joint
2.2.6.1. Simple interlocking joint
2.2.7. Mortice and tenon
2.2.7.1. Jointing flat rectangular sections of timber at right angles
3. Main categories
3.1. Hardwood
3.1.1. Trees
3.1.1.1. Deciduous trees (which lose their leaves in autumn) / broadleaf
3.1.1.1.1. They are harder to work with hand tools than softwood trees
3.1.1.1.2. They are darker in colur or have distinctive colours
3.1.1.1.3. Thay shed their leaves seasonally
3.1.1.1.4. They are slow growing and cannot be cultivated
3.1.1.1.5. They are more expensive to use for timber
3.1.1.1.6. They are selected for their decorative appearance
3.1.1.1.7. They are usually left undecorated except for varnish or polish
3.1.1.2. Tropical trees
3.2. Softwood
3.2.1. Trees
3.2.1.1. Coniferous tress (which remain green throughout the year)
3.2.1.1.1. Features
4. In engineering, categories
4.1. Solid wood / structural timber
4.1.1. Structure
4.1.1.1. Natural with grain and knots
4.1.2. Tree types
4.1.2.1. Softwood
4.1.2.2. Hardwood
4.1.3. Using
4.1.3.1. Support loads in a structure
4.2. Engineered wood
4.2.1. Tree types
4.2.1.1. Solid softwood
4.2.1.2. Hardwood
4.2.2. Making
4.2.2.1. Made by bonding layersor by mixing wood particles and bonding them with resin
4.2.3. Types
4.2.3.1. Low-stregth boards
4.2.3.1.1. Particle board (chipboard)
4.2.3.1.2. Medium-density fibreboard (MDF)
4.2.3.2. Stronger boards
4.2.3.2.1. Orientated strand board (OSB)
4.2.3.2.2. Plywood
4.2.3.3. Glue-laminated sections (glulams)
4.2.3.3.1. Can be used as major structural elements such as beams in large buldings
5. Structure
5.1. Pith
5.1.1. A cantral core of woody tissue
5.2. Heartwood
5.2.1. Inner concentric rings of woody tissue
5.3. Sapwood
5.3.1. Outer ligher-coloured concentric rings
5.4. Medullary rays
5.4.1. Lines which radiate from the centre