One of the main characteristics of wood which you have to learn to accept if you’re going to work with this material is that it always moves. It doesn’t matter what kinds of measures you take to try to prevent it from moving, wood will still always find a way to expand and contract. That’s because wood is an organic product. As such, it will behave quite differently than something made from plastic or some other man-made substance.
In this article series, we’ll take a look at some of the reasons behind wood’s natural tendency to stay in motion. We’ll also consider some ways how you can learn to better accommodate the movement of wood in different situations.
Why Does Wood Tend to Move?
In short, wood moves because of how it is structured. It functions similarly to a group of straws that have all been stuck together. Living, growing trees draw in the water and nutrients they need to thrive from the ground through these straw-like tubes. The wood grows in part as a result of this moisture intake.
When a tree is felled and sawn into lumber, these tubes are severed. The moisture slowly begins to drain out of them, causing them to constrict. This process continues when the wood is stored in hot, dry air or when it is kiln-dried.
If the wood is exposed to damp weather conditions, those tubes can begin to fill up with water all over again. When new lumber is brought to a lumberyard or transported to a job site, it takes a while for the wood to acclimate to its new surroundings. Reaching equilibrium can take days or even weeks.
What Are Some Ways to Slow Wood’s Natural Movement?
There are several methods that people use to try to prevent the wood from moving due to this continual intake or loss of moisture. These include kiln drying the boards, sealing off the ends, and applying a finish, to name a few methods. None of these attempts to stop wood from moving will ever prove to be completely successful. That’s why it’s important to accept the fact that wood is going to move and to plan your project to accommodate its expansion and contraction.
Anticipating the Movement of Wood
Once you’ve acknowledged that the wood you’ve chosen for your project is bound to move, do all you can to educate yourself about the nature of that movement. This will help you more accurately predict that movement and plan accordingly. For example, each species has its unique characteristics, including its tendencies to move in certain ways in specific situations. The more you learn about the species of wood your using, the better you’ll be able to know the proper way to use it.
In our next article in this 2 part series, we’ll take a look at some of the other types of movement which you can expect wood to experience. These would include noting the difference between tangential and radial shrinkage. We’ll also examine some techniques that will help you avoid potential problems.