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?

3 comments

3 Comments

the_diana2mo 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.

oscarwilliams2mo ago

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.

felix4781mo agoMost Upvoted

Did you ever figure out if the wood had enough time to settle before installation? I've seen walnut act up like that when it was cut and finished too quick.