What is Spalted Wood and What Can it Safely be Used For?

For decades, maybe even centuries, the natural patterns and intricate details that are exhibited in wood that has spalting within it has captivated the hearts and minds of the creative wood worker.

The feature that we call spalting is a natural process and is one that allows us to capture a snap shot of that process in the wood and display it in a hand-crafted item.

Because of this it has caused a good number of creative wood working types to go looking for this remarkable wood to make the next generation of items that can be enjoyed by others. We include ourselves in this group.

Every wood species has inherent design limitations, and spalted wood takes these to another level so the challenge to us as wood workers is to design around the damage caused by the spalting so we can maximize the beauty while maintaining the required strength that is needed in any particular piece.

To help you get more of an understanding of this feature wood, we have put this article together to address the question about what can spalted wood be used for. Read on for more.

How is spalted wood created?

Spalted wood is formed when certain strains of fungi gain access into the wood and begin to decompose the wood generally while the wood is still in log form and in contact with the ground.

This is a natural process that allows the living vegetation to re-use the nutrients that are locked up in the dead wood as they are made available through the rotting actions of the fungi. It is how the rainforests of the world keep on growing.

As wood workers, we can intervene in this process at specific times when the wood is still structurally sound enough to work with, but has the tell-tale patterns and colors that the fungi create as they digest the lignin in the wood.

It is a very narrow window where we can use the wood before it becomes useless for woodworking projects.

When a tree falls and is left alone, the natural systems step in and begin the process of converting that wood back into soil and nutrients. The environment should be moist and the wood should be in contact with the ground for the wood to decay at a fast rate, and this is where the rainforests shine.

To see the process in action, all you need do is observe a log or section of wood that is in the right conditions and when you see mushrooms growing from the wood, it can be considered a target for a wood work project, with the disclaimer that the decay may have made the wood unusable already.

Is spalted wood harmful?

There is no risk to wood workers if we are handling the wood but once we start creating dust there is some risk from the fungal spores. While this is a common belief, we do wonder if this is the case in reality. More on this topic to come.

The wood species should also be checked for toxins and aggressive chemical components. We have a list of these woods titles “17 woods that are dangerous to woodworkers” for you to investigate.

The patterns we see as spalting is the evidence of the digestive process that fungi use to survive, and it is not a harmful deposit left there to kill bad wood workers.

The way fungi consume wood is through an external digestive process and the “juice” is taken back into the fungal body to then use to grow. This process leaves stains, and we see them as attractive patterns to be used for artistic purposes.

So in the end, because we cannot say with certainty that spalting is not harmful to use in woodwork hobbies, treat it as a risk and take appropriate steps to control those risks.

Is spalted wood strong enough for furniture making?

Sometimes the damage caused by the spalting process weakens the wood fibers so much that the wood basically becomes useless for wood working. If you are fortunate enough to come across some good spalted wood that is still sound, it is entirely possible to use this wood for furniture making.

It is incumbent of the wood worker to make the judgement call on how strong the wood actually is, and we suggest to err on the side of caution in regards to the furniture item to be considered.

Spalted wood is good for table tops where the wood can be supported out of sight, and this allows the spalted patterning to be on full display. Structural elements should be made with sound wood to remove the risks of collapse if the decay from the spalting is more advanced that first impressions.

We don’t recommend building chairs from spalted wood due to the structural risks involved, but any piece that uses flat panels can be considered if the wood is sound. Suspect wood should be left for smaller craft projects where strength is not as imperative.

Can spalted wood be safely used for making kitchen items?

Yes, spalted wood can be used for making kitchen items like rolling pins, spoons, and similar. As discussed above, the strength of the wood should be tested before committing to the planned project.

As is discussed in this article titled “Is spalted wood safe for food contact?” there is reason to treat the wood with respect, and the final finish is very important for a long life with little risk from the wood.

Understanding spalting and how it can be stopped is just a small part of the education that wood workers gain through the making of great projects. Often times the wood will be turned on a lathe, and this has potential risks that need consideration. “Is spalted wood dangerous to turn?” covers these risks.

Conclusions.

Spalted wood is safe to use if the wood is sound, if it still has strength, and can be finished to stop the decay process. There are many items of furniture that have been made over time with this type of timber and while they are all individual, they all needed to be designed around the weaknesses that come with spalted wood.

Don’t let a little rot put you off from using this timber, because the end result can often be spectacular.

Article written and edited by Tim Blanch for Woodwork Hobby Report.