Before cleaving a piece of timber we remove the bark using a drawknife or a debarking spade so that we are able to see where the split is running.

Timbers less than approximately 15cm in diameter and up to 3m long are placed in a cleaving brake, (a wooden structure to hold the material while its being cleft which helps to control the split), and split with a froe.

Large diameter timber (more than 15cm) is split with wedges for the first, and sometimes subsequent splits, to make the timber more manageable.

Wood is ideally split two to three months after felling, though larger timber can be left for several years. If left too long the timber will have dried out and won't respond as well to cleaving; if the timber is too green, e.g. within the first week of it having been felled, then it may split too easily and it will be hard to control the split.

The idea behind cleaving is that the split will always run towards the fibres under the most tension. We use a cleaving brake because it enables us to easily control which fibres are under the most tension.

For example, when splitting a piece of timber in half the split should run centrally. However, if it begins to run into either half we can position the timber in the brake with the larger half on the bottom, and by pushing down on that half while using the froe to continue to cleave it, the split should right itself. Of course it doesn't always work! It is easier to cleave timber in half because when going into three it is harder to control the tension, as one side is bigger.

Not all species of timber cleave well, and even those that do often have awkward knots and twisted grain that will make it difficult to control the direction of the split.

We cleave:-

Oak (Quercus robur / petraea) for:-
Shingles
Batten

Draw Knife and froe for small work.

Splitting with a cleaving brake and froe.

Shaving with a draw knife.