Just realized how much wood moves in a year after a job in Phoenix

I was working on a custom built in for a living room here in Phoenix last summer, using some nice 8/4 walnut. I let it sit in the shop for a week, milled it, and installed it with what I thought was a good gap. Came back for a small fix this week, almost a year later, and the panel had shrunk a full quarter inch. The homeowner pointed it out, and I felt pretty bad. I looked it up after and found out that wood can move about 1/4 inch for every 12 inches of width across the grain with the seasons, depending on the species and humidity. I always knew it moved, but seeing that exact number from a woodworking site really hit home. I guess the dry air here just pulls moisture out like crazy. How do you guys in really dry or really wet places figure your seasonal gaps?

2 comments

2 Comments

the_diana5d ago

Phoenix humidity swings are no joke, but a quarter inch on a built-in seems extreme. Most furniture grade stuff I've seen moves maybe an eighth over a year if it's properly dried. Are you sure that walnut was fully acclimated to the shop before you milled it? Sometimes wood gets shipped in from a humid place and needs more than a week. I'd check your shop's moisture meter against a known sample.

oscarwilliams5d agoMost Upvoted

You make a good point about checking the meter, @the_diana. I had a maple tabletop do something similar after a cross-country move, even though it sat in my garage for a month. Wood just has a mind of its own sometimes.