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Log splitter

Log preparation

Quality and standards

Boilers and stoves require high quality logs. Key characteristics are:

  • Moisture content
  • Species type
  • Size of log
  • Contamination (e.g. soil)
  • Bark content

Quality criteria are set out in European standards (CEN 355). Within these standards are properties for logs.


Logs should be dried for one to two years before they are ready to be used as fuel. The exact drying period required depends upon when then tree was cut.  If a tree is felled in spring or summer it will have a much higher moisture content than if it is felled in autumn or winter and will require a longer drying period. Drying periods will also be determined by local climatic conditions.

Small roundwood should be dried in stacks, raised up from the ground, in a sunny place, exposed to the prevailing wind.

The stacks should be covered from rain, using either a roof or waterproof/semi-permeable sheeting. The ends of logs should be uncovered since this is where most moisture loss takes place. Air should be allowed to flow through the stack.

To aid drying, bark can be scored, or partially or fully removed. If they are over 15 cm in diameter, logs should be split to accelerate drying.


The majority of log splitters are simple hydraulic devices, powered either through the electric mains or a small petrol engine. The hydraulic device pushes the log against a sharp axe like blade which cuts the log in two.

Log splitters are often rated by the tons of pressure they can generate, the higher the pressure rating, the greater the thickness or length of the rounds that can be split. Most log splitter models for home use have a rating around 10 tons; professional hydraulic models may exert 25 tons of pressure or more.

Other types are:

  • Manual log splitters which use levers to force logs through a sharpened blade assembly
  • Screw or 'corkscrew' log splitters, driven directly from an agricultural tractor's power take-off shaft where the splitter is mounted on the three point linkage.

Firewood processors

Firewood processors consist of a log cutter (typically a long-blade chainsaw welded in place to the frame) and a log splitter.

In a standard firewood processor, logs are fed into the processor by a feed-in system or log deck. The log is then sawed to a preset length, and a hydraulic ram pushes the sawn portion against a steel plate with a sharpened edge, which splits the log in half. An operator rotates the split half and resets it for another pass against the splitter, which yields log quarters suitable for firewood. A hydraulic lift is useful in lifting logs onto the log deck for processing, although a large tractor can also perform this function

Firewood processors are essential tools for cutting and splitting large volumes of firewood efficiently for the commercial market but can be costly, so it is worthwhile looking into purchasing second hand machinery from a dealer.