While the other three seasons may be more popular for exterior projects, winter certainly holds opportunities for some jobs to be completed. Whether it’s a repair that’s necessary for safety right now or an addition or renovation that needs to be completed by spring, we understand that sometimes winter projects cannot be avoided. In addition to suggesting a high-quality insulated bottle that will keep your beverage of choice hot, we have one main recommendation for you as you work with wood this winter: leave room for movement.
Wood Movement Basics
While you always need to allow for wood movement, when you build during the coldest and driest time of the year, you need to leave room for expansion. Essentially, wood fibers act like a bundle of straws, which swell as they absorb water and then contract as they shed moisture. During winter, boards are at their smallest size in colder parts of the U.S. (This is true indoors as well as outdoors, too. Artificial heat creates an environment similar to that of a kiln, due to the warm, dry air that keeps us cozy.) While it might seem challenging, it’s actually simple to plan for movement during the extreme cold: you know that wood will move in only one direction.
Winter Wood Movement
Because any wood you install – moulding, siding, flooring, or whatever – will be the narrowest it will be all year, you can easily calculate the minimum gap to include. Whether it’s around a drawer front, between siding boards, or around a floating floor, you know that the gap with which you install the boards will be the largest that it will be throughout the year.
Wood Movement According to Species
While woodworking may well be considered an art form, calculating wood movement isn’t art; it’s science. It’s fairly easy to calculate wood movement based on species, using various charts and tools. You could check out the wood species pages on the J. Gibson McIlvain Lumber website. For each species we carry, you’ll see the ratio of radial shrinkage to tangential shrinkage. (For quartersawn boards or boards with vertical grain, you’ll want to reference mainly the radial shrinkage, while with flat sawn boards, tangential shrinkage will be more significant.)
If you’d rather have all the numbers right at your fingertips, you can install The Woodshop Widget, which is available for both iOS and Android devices. Because wood is an organic material and each board is unique, such numbers are only guidelines; other factors will influence wood movement, and you can play it safe by allowing for a little bit of extra room.
The fact remains that winter installation comes with greater risks than a summer installation. If you poorly plan spacing during the summer, the worst trouble you may have is unsightly gaps. With a winter install, though, not allowing enough space for expansion can result in damage – from counter tops that split and crack to flooring that warps and buckles. As long as you allow for enough wiggle room, though, you can ensure a successful winter install.
