WOOD! What is wood? An organic, natural composite of cellulose fibres A living structure combining strength & flexibility Contains WATER, even when dried, making it pliable. Weight for weight has the best engineering properties of any material Excellent insulator compared to metal, plastic and concrete

Types of Timber Softwood Comes from EVERGREEN trees with needles. Typically grows quickly and in colder climates making it relatively cheap to buy. Hardwood Comes from DECIDUOUS trees which grow slowly in warmer climates making it more expensive. Is denser than softwood with a tighter grain. The terms soft and hardwood are misleading as hardwoods are not necessarily hard or softwoods soft. Balsa (a hardwood) is actually softer than most softwoods. Though evergreens do tend to be less dense.

Types of SOFTWOOD Pine Pale yellow with brown streaks and knots. CHEAP LIGHT QUITE STRONG DURABLE Cedar Pale red and fragrant with a uniform, straight grain. DURABLE NATURAL RESISTANCE TO ROT EASY TO WORK LIGHT GOOD INSULATOR

Types of HARDWOOD Teak Yellow/dark brown with a tight grain and high natural oil content. STRONG DURABLE CURVES WELL / PLIABLE NATURAL RESISTANCE TO RAIN Mahogany Pink/reddish brown with an attractive, interlocking grain. FAIRLY STRONG ATTRACTIVE DURABLE EXPENSIVE

Oak Light to medium brown with an open grain. STRONG HARD TOUGH HEAVY POROUS Ash Pale, light golden brown with an open grain. FLEXIBLE TOUGH DURABLE EASY TO WORK

Beech White – pinky brown with a close grain. HARD STRONG WARPS EASILY TOUGH SUSCEPTABLE TO SHRINKAGE Elm Light to medium brown with an interlocking grain. PLIANT / BENDS WELL TOUGH RESISTS SPLITTING DURABLE IN WATER RESISTS DECAY WHEN WET

Types of Manufactured Board PLYWOOD Layers of thin wood sheets glued together at 90 degree angles to each other. Often veneered. STRONG IN RATIO TO WEIGHT PLIABLE / CAN BE BENT RESISTANT TO SPLITTING, WARPING BLOCKBOARD Strips of softwood between 7-25mm thick are glued together side by side and sandwiched between 2 layers of veneer. CHEAP STRONG NOT SUITABLE FOR OUTDOOR USE

CHIPBOARD Small wood particles mixed together with glue, heated and pressed in to sheets. Usually plastic veneered. VERY CHEAP CAN BE MADE FIRE RESISTANT NOT VERY STRONG ABSORBS WATER AND SWELLS RESISTANT TO WARPING (IF DRY) MDF – Medim Density Fibreboard Softwood waste is broken down into tiny fibres, mixed with urea formaldehyde, heated and compressed into panels. Often veneered. CHEAP DOESN’T WARP WHEN DAMP EASILY MACHINED CAN BE MADE FIRE OR WATER RESISTANT

HARDBOARD Similar to MDF but denser. Made from compressed, glued fibres. Has one smooth side and one textured. CHEAP EASY TO WORK POOR RESISTANCE TO MOISTURE DOES NOT SPLIT OR CRACK

Which wood for whichpurpose ?

TEAK Resists moisture Pliable/curves well Durable ELM Resists decay Durable in water Tough ASH Easy to work Flexible Tough

What wood might this be made of? PLYWOOD!

And these? Mahogany Oak

Or these? MDF Pine

Finishes Sanding Planing

Finishes Varnishing Staining

Finishes Bleaching Waxing

Finishes Oiling Distressing

Finishes Lacquering

Health and Safety Wood manufacturing has one of the highest accident rates in the industry ( Wood dust can create health problems if a person inhales it or is exposed to it over a long period of time Dust/chippings can get in eyes Wood dust can be slippery

Health and Safety Can get splinters if wood is untreated Wood can be quite heavy Machinery is dangerous eg. Saws, drills Electrical equipment can break or be faulty Noise of some machinery can cause heath problems after long exposure Fire risk – both wood/wood dust and the products that treat it e.g varnish, paint

Sustainability Wood regarded as sustainable material Grows naturally Renewable Uses CO₂ that humans create burning fossil fuels, breathing etc.

Sustainability LCA (Life Cycle Assessment) method rates wood highly in sustainability. Evaluates materials of course of their life.

Sustainability Wood is good for environment in terms of: Global warming potential Resource use Embodied energy Air pollution Water pollution

Sustainability Global warming potential Stores CO₂ Uses it as energy Lower energy usage than in making of plastic and metal

Sustainability Resource use Resource is renewable Usually easily recyclable/reusable Durable/long term

Sustainability Embodied energy Sum of all energy used to produce wood Lower than other materials such as plastic and metal From raw material extraction, transport, manufacture, assembly, installation through to dis-assembly, deconstruction and decomposition

Sustainability Air pollution When wood is living tree good for air pollution Extraction and construction is lower than most resources Only bad for air pollution when burned

Sustainability Water pollution Low level pollution concerning wood and water Rated against other resources

Recycling Pros Environmentally friendly Raises awareness of deforestation Saves landfill space If can be used in place of plastic/metal, saves non renewable sources Cons  Recycled wood costs less, but recycling costs high and time consuming  Demolition becomes more time consuming and complicated  Not well established trade

Recycling Wood can be recycled in different ways Become fuel Flooring/decking Beams Mulch Can either be broken down (fuel/mulch) or kept in original condition and refinished (beams/flooring)

By Ellie, Laura and Sophie