A customer calls in July. There's a crack in the seat rail of the chair you built them three years ago. They can see it and they're worried. The natural move: tell them to bring it in, and you'll re-glue it.
July is the worst month for this repair.
Here is why. In summer, wood absorbs moisture from the air. The fibers expand. In a mortise-and-tenon joint, that expansion loads the joint in tension. The crack is at its widest. The faces are separated. When you apply adhesive to a joint in that condition, you are bridging a gap under active tensile load. The glue cures against an open joint and sees full summer stress the moment it's done. Most of those repairs fail within a season or two. Not because of poor technique. Because of timing.
In February, the same joint is under compression. Winter air is dry. The fibers have contracted. The crack faces are touching. Adhesive applied now cures at maximum surface contact, under zero tensile stress. The repaired joint sits undisturbed for nine months before the next summer cycle begins.
The protocol is two appointments, not one.
When the customer calls in July: go see it. Measure the check depth with a feeler gauge or a piece of shim stock. Write it down. Tell them to call you in February.
When they call in February: that's the repair visit.
This is the finding that matters: the inspection window and the repair window are six months apart. Summer shows you the crack at full width — easy to measure, easy to evaluate. Winter gives you the geometry you need to fix it properly. Conflating those two moments is the source of most poor repair outcomes on solid-wood case furniture and chairs.
One more thing. Some checks don't need repair at all. In a coastal climate — Vancouver, Victoria, the PNW — a check under about 0.7 mm is likely below the stress threshold at which cracks actively propagate. In a drier interior climate like the Okanagan, that number is closer to 3 mm. Measure it now. Measure it next summer. If the number hasn't moved, the crack is probably stable. Only repair what's growing.
The last change: add one line to every delivery receipt for solid-wood furniture going to a wet climate: "If you see a check in the wood, call us in February." Not when they notice it. February.