WOOD!

1. 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

2. 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.

3. 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

4. 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

5. 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

6. 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

7. 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

8. 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

9. 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

10. Which wood for which purpose ?

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

12. Quiz time! What wood might this be made of? PLYWOOD!

13. And these? Mahogany Oak

14. Or these? MDF Pine

16. Finishes • Sanding • Planing

17. Finishes • Varnishing • Staining

18. Finishes • Bleaching • Waxing

19. Finishes • Oiling • Distressing

20. Finishes • Lacquering

21. Health and Safety • Wood manufacturing has one of the highest accident rates in the industry (www.hse.gov.uk) • 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

22. 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

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

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

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

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

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

28. 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

29. 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

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

31. 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

32. 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)

33. By Ellie, Laura and Sophie