Making timber planks involves several key stages, starting from felling the tree and culminating in a finished piece of lumber ready for various uses. The process begins with harvesting the raw material.
From Forest to Sawmill: The Initial Steps
The journey of a timber plank starts in the forest.
- Felling the Tree: Mature trees are carefully selected and cut down using saws.
- Bucking the Trunk: Once a tree has been cut down, the trunk is then cut into logs of manageable lengths. This process is called bucking. The length of the logs depends on the desired lumber size and transportation capabilities.
- Transport: These [logs] are then transported to a sawmill, often by truck, train, or sometimes by floating them down rivers, depending on the location and infrastructure.
Processing at the Sawmill
At the sawmill, the logs are transformed into lumber. This is where the log is broken down into usable sections.
Splitting Logs into Flitches
A critical step at the sawmill is the initial breakdown of the log. [Logs] are then split into flitches (a large plank or section of wood that is unfinished). A flitch is essentially a large piece of wood cut from the log, often with the bark still on the edges.
Cutting Methods
The way a log is split into flitches and subsequently into planks varies significantly. How it is split will depend on the type of tree and what it will be used for. Different cutting methods are used to maximize yield, achieve specific grain patterns, and minimize warping. Common methods include:
- Live Sawn (Through and Through): Cutting the log into parallel planks without rotating it. This method yields wide boards and a mix of grain patterns.
- Plain Sawn (Flat Sawn): The most common method. Cuts are made tangent to the growth rings. This produces the familiar cathedral pattern in the grain and is the most efficient method in terms of yield.
- Quarter Sawn: The log is first quartered lengthwise, then cuts are made perpendicular to the growth rings. This method yields more stable boards with a straight grain pattern (often displaying ray flakes in some species) but is less efficient in terms of yield.
- Rift Sawn: Similar to quarter sawing, but cuts are made at a specific angle (usually 30-60 degrees) to the growth rings. This produces very stable boards with a consistent linear grain pattern but is the least efficient and therefore most expensive method.
Here's a simplified comparison of common sawing methods:
| Method | Grain Pattern | Stability | Yield |
|---|---|---|---|
| Plain Sawn | Cathedral | Moderate | High |
| Quarter Sawn | Straight, Ray Flake | High | Moderate |
| Rift Sawn | Linear | Very High | Low |
Further Processing
After being sawn into rough planks or flitches, the timber undergoes further processing:
- Drying: The moisture content of the wood is reduced. This is crucial to prevent shrinkage, warping, and cracking. Drying can be done naturally by air-drying or artificially in kilns for faster, more controlled results.
- Planing/Milling: The rough-sawn planks are run through planers to smooth the surfaces and dimension the lumber to standard sizes (e.g., converting a nominal 2x4 to an actual 1.5" x 3.5").
- Finishing: Depending on the intended use, the timber might be sanded, graded based on quality, and sometimes treated with preservatives.
These steps transform a raw log into the finished timber planks used in construction, furniture making, flooring, and countless other applications.
