Timber

Question 1

What are the key features of softwood?

Answer 1

-comes from coniferous
-grows faster than hardwoods making it cheaper
-easy to with, often used as a building material
-relatively renewable
-have needles instead of leaves
-it grows tall and straight making it easier to manufacturer which can be cut long and straight planks of wood

Question 2

Name 3 examples of softwood, and there use.

Answer 2

Scots pine (fences, box), Parana pine spruce, yellow cedar(poles), European redwood (beams)

Question 3

What are the key features of hardwood?

Answer 3

-come from deciduous or board-leafed trees
-they are special as the are deciduous meaning they lose their leaves in the autumn/winter months
-they grow slower than softwoods making them more expensive
-strong wood density

Question 4

Name 3 examples of hardwood, and there use.

Answer 4

beech (children toy), oak (good for building), mahogany, teak (ship building), balsa

Question 5

What are the two types of seasoning

Answer 5

Natural, kiln

Question 6

Define seasoning

Answer 6

removal of excess moisture for newly swan timber

Question 7

What is kiln seasoning?

Answer 7

-it is like factory process
-steam, heat and fan can control the moisture

Question 8

Give a pro and a con for kiln seasoning

Answer 8

Pro:
-accurate water content achieved
-12% or lower moisture content achievable-controllable
-kills bugs and fungus
-fast
Con:
-expensive

Question 9

What is natural seasoning?

Answer 9

-timber is seasoned by subjecting it to the natural elements such as air or water

Question 10

Give a pro and con for natural seasoning?

Answer 10

Pro:
-cheap
-some say the timber is stronger than kiln-seasoned
Con:
-very slow (a year per inch thicknes）
-bugs and fungus survive
-water content is hard to control accurately
-end of planks can split

Question 11

What is timber defect?

Answer 11

any irregularity occurring in or on the wood that lowers its strength durability utility value or appearance

Question 12

What is warping?

Answer 12

this can occur when the timer is not stored flat. If it is not laid flat, wood can become be bent or twisted

Question 13

What is knot?

Answer 13

-a branch was attached to the tree
-live knots are ok and can be decorative
-dead knots need to be avoided

Question 14

What is the problem of dry rot? How is it caused?

Answer 14

-serious problem— incorrect seasoning or poor building maintenance
-caused by timber being over 20% moisture content are not ventilated

Question 15

Define woodworm

Answer 15

the common furniture beetle lays edges on timber. The larvae eat the wood for a year and then emerge as adult beetles in the spring. “Frass”, or wood dust is a sure sign of woodworm.

Question 16

Explain the difference between steam bending and laminating

Answer 16

The process

Question 17

What is FSC?

Answer 17

-global organisation to verify timber is sourced from ethical places

Question 18

What is manufactured boards?

Answer 18

-comprise a range of sheet materials produced by pressing and bonding together wood particles, fibres or veneers to achieve particular characteristics - and to create a use for what would otherwise be discarded as waste

Question 19

What are the advantages of manufactured boards?

Answer 19

Pro:
-available in large sizes and thickness
-designed for specific purposes, such as marine ply
-use waste from processing timber
-uniform - few imperfections
-do not split
-available in ready finished format - like veneers

Question 20

Name 3 types of manufactured boards and the key features

Answer 20

Blockboard:
-softwood strip core
-bonded with adhesive
-covered with sheet of plywood
-finished with a veneer
Hardboard:
-pulped fibres pressured until fibres bond together
-smooth one side, rough on the other
-not as strong as other boards - cheaper
-used in non structural situations - backs of cupboards
Chipboard:
-small chips bonded with resin, compressed into sheets
-not as strong as ply or blockboard - much cheaper
-covered in a plastic veneer
-used in indoor furniture
Medium density chipboard (MDF):
-fine wood dust and resin pressed into a board
-worked easily
-strong (resin)
-used in lots of indoor applications
-easily finished/painted
Plywood:
-veneers of timber bonded by resin and pressure
-each at 90 degree to the other
-lots of sizes available
-can be manufactured for different purposes:
-flexi ply
-laser ply
-marine ply