Different Types of Wood and their Properties

Timber:

• Natural, renewable resource;
• Can be joined and machined in many ways;
• Changes in moisture content – can warp and twist if not properly dried;
• Can have irregular strength, due to knots and grain;
• Comes in standard sizes;
• Doesn’t come in large sheets;
• Rots easily – susceptible to fungal attack (most need chemical treatment (i.e. tanalising) if used outside, but some don’t, i.e. cedar)
• Relatively expensive to buy.

Manufactured boards:

• Can be produced in large sizes;
• Relatively cheap;
• More stable, because don’t have grain running through them in one direction;
• Thin sheets can be bent around slight curves;
• Difficult to join;
• Exposed edges often need to be treated;
• Thin sheets need to be supported by a frame or they sag / distort.

Veneers

• Thin layers laminated onto another surface;
• Economical, since little of the tree is wasted.

Plywood

• Made from veneers of hardwoods laminated together;
• Stronger than normal wood.

Chipboard

• Made from wood fibres (from wood waste) glued together with synthetic resin;
• Disintegrates if left exposed to wet conditions;
• Sometimes made with a wooden or plastic veneer for cheaper furniture;
• When worked, dust masks should be used, to protect lungs from the fine fibre.

Medium Density Fibreboard (MDF)

• Smoother, better quality chipboard;
• Readily joined using adhesives;
• Can produce an excellent smooth finish;
• Readily available in large sheets.

[demonstrate a working knowledge of natural timbers and understand their classification, properties and uses

understand the advantages and disadvantages of working with manufactured boards compared with solid wood – IG]

understand why timber is seasoned and how to care for timber during storage and construction

understand steaming and bending of timbers and have knowledge of adhesives’ curing times and
strengths

demonstrate a working knowledge of the following manufactured boards: plywood, blockboard,
chipboard, hardboard and MDF

[The working properties, stock forms and sizes, common uses and environmental impact of the following:
– softwoods
○ pine, cedar, fir, spruce or equivalent local softwood
– hardwoods
○ beech, oak, ash, teak or equivalent local hardwood.]

[composite products: manufactured boards
○ chipboard
○ engineered wood
○ medium density fibreboard (MDF)
○ plywood
○ blockboard]

Students should also be familiar with composite materials (a manufactured material that combines two or more materials with different properties), smart materials, modern materials and biodegradable materials.

[coming soon]