How much does White Fir move?
White Fir has moderate seasonal movement, typical of many furniture woods. Standard wood-movement precautions on wide panels apply.
A 24-inch-wide White Fir panel, across the seasons
Going from humid (summer, unconditioned) (about 13% moisture content) to dry (heated interior, winter) (about 6%), a 24-inch-wide White Fir panel changes width by roughly:
0.44″
Flatsawn (plain-sawn)
Tangential shrinkage 7%
0.20″
Quartersawn
Radial shrinkage 3.3%
Computed with the USDA Forest Products Laboratory dimensional-change formula from published green-to-oven-dry shrinkage figures. Real-world movement varies with your actual humidity range, board width, and how the wood was dried, this is a representative estimate, not a guarantee.
Flatsawn vs. quartersawn White Fir
Flatsawn White Fir moves about 2.1× as much as quartersawn across its width (tangential shrinkage of 7% versus radial 3.3%). That’s why quartersawn stock is prized for tabletops, wide panels, and anything where seasonal movement would cause problems, it moves less and stays flatter. The gap is large for White Fir, so quartersawing makes a real difference here.
Run your own numbers
These figures use a 24-inch panel and a typical seasonal swing. For your exact board width and humidity range, use the interactive calculator, White Fir is already loaded with its verified shrinkage data.
Open the wood movement calculator →Managing White Fir movement in a build
Wood moves across its width, not its length, so the wider the panel, the more it matters. The classic precautions apply: let the wood acclimate to your shop before building, attach wide tops with fasteners that allow movement (elongated screw holes, buttons, or figure-8 clips), avoid gluing solid panels rigidly across the grain, and account for seasonal swing in fitted parts like drawers and doors. For White Fir specifically, its moderate movement means standard practice is usually enough.