Developing a working knowledge of wood movement (see Part 1) can have a huge impact on how effectively you’ll be able to work with this extraordinary medium. If you understand how and why wood moves and what to do to mitigate problems posed by its movement, you’ll be well on your way to completing successful wood construction projects.
One of the most challenging realities of working with wood is coming to grips with the fact that movement isn’t uniform. As wood dries out, the ends of boards typically become dry faster than the center of the boards. This makes sense when you think about the moisture dripping from the ends of the wood’s straw-like fibers. Because wood has this tendency, it has to be handled carefully, especially during the initial drying process. Though it will continue to move after reaching equilibrium, the movement after that point will greatly diminish as the moisture exchange slows down.
Here are a few tips for minimizing the moisture expansion and contraction of your wood.
1. Avoid leaving wood in direct sunlight.
When wood is left out in the sun, it can dry out too quickly. This can cause warping, cupping and twisting of the wood.
2. Allow plenty of ventilation when stacking wood.
This can help your wood dry more evenly. You can even put little pieces of wood that have already dried out in between the drying boards; these little pieces of wood are called "stickers." The extra room will allow air to circulate so the wood can dry better.
3. Allow acclimatization time in a wood-friendly area
When it comes to acclimatization, you simply can’t rush wood. It has to have plenty of time to reach equilibrium after experiencing a change in surroundings. Make sure to keep the boards in a well-ventilated environment out of direct sunlight until the process is complete.
Thankfully, if you purchase kiln dried lumber for your wood construction project, you’ll start out with a product that’s already pretty stable as long as you continue to treat it well. Depending on the species of wood, you’ll need to let it equalize before continuing with your project. The more drastic of a climatic change the wood goes through when moving from the lumber yard to the construction site, the more time it may take to acclimatize properly.
Before starting any project involving wood, take the time to read and research which species of wood are most recommended for various uses. Talk to others who have completed successful projects like the one you’re getting ready to start. Movement is just one important factor to consider when determining which species of wood will be most suitable to the type of undertaking you have in mind.
Wood originally comes from a living organism. As such, it will always remain susceptible to expansion and shrinkage due to changes in humidity levels. If you take the necessary time to learn about why wood moves, how it moves, and how its tendency to move impacts various species of wood, you’ll be better equipped to work with this amazing natural resource.