Timber

Question 1

What forms do timber planks come in?

Answer 1

Rough Sawn

Planed All Round

Question 2

What is the difference between rough sawn and planed all round?

Answer 2

• Planed All Round has a smoother finish, thus finishes can be applied more easily
• Rough Sawn is more absorbent

Question 3

What is seasoning?

Answer 3

A process where moisture is taken out of freshly converted wood

Question 4

What is the conversion of wood?

Answer 4

It is the process through which a length of the trunk of a tree is converted into planks

Question 5

What is green timber?

Answer 5

Timber with more than 50% moisture content

Question 6

What is timber?

Answer 6

A plank of wood

Question 7

What is the consequence of uneven evaporation of water when timber is seasoned?

Answer 7

The timber may undergo twisting, cupping and bowing

Question 8

What type of trees do hardwoods come from?

Answer 8

Deciduous

Question 9

Why are hardwoods so expensive?

Answer 9

The deciduous nature of the trees means they take very long to grow

Question 10

What are the two methods of seasoning?

Answer 10

Air Drying

Kiln Drying

Question 11

What are three types of manufactured board?

Answer 11

• MDF (medium density fibreboard)
• Plywood
• OSB (oriented strand board)

Question 12

How are manufactured boards made?

Answer 12

Compression method

Wood is shredded, chipped or pulped, then compressed and heated under high pressure.

Question 13

What is a veneer?

Answer 13

A thin slice of natural timber

Question 14

How are veneers made?

Answer 14

Rotary veneer method

Works like a pencil sharpener with log being rotated and knife slicing a thin layer off log

Question 15

What is the difference between MDF and other man made boards?

Answer 15

MDF does not use adhesive

Question 16

Disadvantages of manufactured boards

Answer 16

• tools can blunt easily due to adhesive in the board
• adhesives may contain hazardous particles
• boards are prone to moisture if not treated

Question 17

Advantages of manufactured board

Answer 17

• no twisting, cupping or splitting like natural wood
• smooth finish
• available in many finishes like laminate and veneers

Question 18

What are the common manufactured boards and their characteristics

Answer 18

• blackboard : tough, heavy and finishes well
• hardboard : flexible, even strength, inexpensive and easily damaged unless treated
• OSB : strength in all directions, water resistance- used in construction hoarding and exterior house building

Question 19

What are additional softwood and their characteristics

Answer 19

• redwood: easy to work, rot resistance and machines well - used for outdoor furniture, beams decking, posts
• cedar: easy to work, can blunt tools, finishes well and rot resistance - used for fences, roof finishes and cladding