Timber Sources: Seasoning and Conversion
How a felled log becomes usable timber: converting a log into planks, seasoning it to remove moisture, the choice of air or kiln seasoning, and the manufactured boards made from wood.
Justify the choices, the way you are assessed
Free interactive practice on the decisions the assessment actually asks you to justify.
Start revising freeWhat you'll cover
From log to plank
A tree cannot be used as timber the moment it is cut down. It has to be sawn into usable pieces and dried out first. This module follows a log from the forest to a usable, seasoned plank, and looks at the manufactured boards that are made from wood.
Timber vocabulary
Learn these four terms before you study the processes.
Air vs kiln
Timber can be dried in two ways, one slow and one fast.
Three different jobs
A top answer keeps three timber processes in the right order and does not muddle them: first the log is converted, then the timber is seasoned, and only a finished piece is tanalised to protect its surface. Each one is a separate job.
Match the method
- air seasoning
- kiln seasoning
- plain sawing
- quarter sawing
- drying timber slowly outdoors
- drying timber fast in a heated chamber
- quick, cheap cuts that may warp
- slower cuts that stay more stable
Match the board
- plywood
- MDF
- chipboard
- a veneer
- thin layers glued with the grains crossed
- fine wood fibres pressed with glue
- wood chips bonded together
- a thin slice of real wood on a surface
Name the process
Timber is dried after felling so that it does not warp later. What is this process called?
- Seasoning.
- Conversion.
- Tanalising.
- Sanding.
Why season timber
Select the TWO reasons timber is seasoned before it is used.
- So it is less likely to warp or twist.
- So it is less likely to rot.
- To make it much heavier.
- To make the surface rougher.
Tree to timber
Put the stages of turning a tree into usable timber in order, earliest first.
- A tree is felled in a managed forest
- The log is converted into planks
- The planks are seasoned to dry them
- The seasoned timber is used to make products
Complete the facts
Drying timber slowly outdoors is _____ seasoning. Drying it fast in a heated chamber is _____ seasoning. Plywood is made of thin layers with the grains _____. A board of pressed wood fibres is _____. A board of bonded wood chips is _____.
Moisture removed
Freshly cut timber has a moisture level of 50 units. After seasoning it drops to 10 units. Subtract 10 from 50 to find how much moisture has been removed. What is the answer in units?
Find the manufactured boards
Tap the TWO of these that are manufactured timber boards.
- plywood
- MDF
- oak
- pine
Which process?
Read each step and choose the timber process it describes.
- A log is sawn lengthways into flat planks
- Planks are stacked in a heated chamber to dry out
- A preservative is put on a finished bench to protect it from rot
Explain the processes
Explain how a felled log is turned into usable timber. Describe conversion and seasoning, and explain why timber must be seasoned before use.
- Explain what conversion is
- Explain what seasoning is and name the two methods
- Explain why timber must be seasoned before use