Every August, we get a wave of calls that all start the same way. A door that closed all spring easily is suddenly catching at the latch. A window that opened without effort in June now needs both hands. Nothing was dropped, nothing was forced, and as far as the homeowner can tell, nothing changed. Except the weather.

Wood is a natural material, and it responds to moisture the way most natural materials do: it absorbs it. Michigan summers bring long stretches of high humidity, and wood doors and window sashes pull that moisture right out of the air. As the wood absorbs it, the fibers swell, and a door or sash that fit perfectly in a dry spring can gain just enough size to catch where it never used to.

The symptoms are specific enough that they’re often easy to recognize. Doors tend to stick at the top corner near the latch or drag along the strike plate, since that’s usually where the tightest tolerance is. Windows, especially older wood double-hungs, get harder to lift or lower and may feel like they’re binding in the track rather than sliding.

Here’s the part that catches a lot of homeowners off guard: this usually is not a hardware problem, and it usually is not an alignment problem, even though it can look exactly like one. It’s the wood itself, temporarily larger than it was two months ago.

That distinction matters, because the instinct to plane the door down or force the window through can create a bigger problem than the one you started with. Wood that’s swollen with summer humidity will shrink back once the season turns and the air dries out. Homeowners who plane a sticking door in August are often the same ones calling in November about a draft or a gap, because the fix that solved the summer problem created a fall problem.

What actually helps, most of the time, is patience and a light touch: a dehumidifier or air conditioning to reduce the moisture load in the room, a little paraffin wax or dry lubricant on the parts that rub, and leaving the wood itself alone until you know whether the swelling is seasonal or something more permanent, like a worn seal or a shift in the frame.

If a door or window has been giving you trouble all August, sending us a photo is usually enough to tell you which one you’re dealing with, and whether it’s worth a service call now or worth waiting out the season.