Charred wood cladding and fencing are unique and durable. Where we have previously dealt with the fire retardancy of charred wood, the characteristic that makes charred wood pest and insect resistant is now being dealt with.

Charred wood is not "bug proof". However, it is insect-resistant. Termites fed on charred wood have been found to be less healthy than termites fed on fresh pine shavings, although the termites still eat the charred wood when they have nothing else to eat. Charring is therefore a deterrent, but not a complete solution to termites and other wood pests.

There is not really a single solution to combating pests such as termites, except: don't use wood in your construction! However, there are many things you can do in the construction or refurbishment of a building to help control pests. The use of charred wood in cladding, flooring and fencing would be one of them, but it is not all-encompassing.

A thorough study of why termites and other pests dislike charred wood has, to our knowledge, not yet been done. However, we can speculate why the charred layer is not favoured by pests. As with fire retardancy, the charring process drives out the lighter and more volatile cellulose compounds, leaving the blackened lignin harder and more stable. As we explained in the article on fire retardancy of charred wood, there are mainly two main components of wood: cellulose compounds and lignin. The cellulose compounds in wood are more volatile, which means they are less chemically stable and therefore easier to disintegrate, releasing energy. The lignin is much more chemically stable and therefore harder to digest.

The softer cellulosic components of wood do not necessarily contain more energy, but the energy is more readily accessible, i.e. if the cellulose-like compounds are largely evaporated and burned during the charring process. This makes the wood less nutritious to termites and other pests.

In addition, we assume that the charcoal compounds that remain after the charring process are probably less palatable to pests. Numerous (chemical) compounds, formed during combustion, are left behind in the charred layer. Many of these are probably not particularly healthy to eat by pests and termites.