Sitka Spruce
Picea sitchensis · softwood · Pacific Northwest · moderate movement
- Janka hardness 510 lbfred oak ≈ 1,290 lbf
- Density ≈ 28 lb/ft³specific gravity 0.4 at 12% MC
- Shrinkage — tangential 7.5%flatsawn width, green → ovendry
- Shrinkage — radial 4.3%quartersawn width
- T/R ratio 1.7 : 1higher = more cupping in flatsawn stock
Shop notes The strength-to-weight champion — aircraft spars, masts, piano soundboards. Clear vertical-grain stock deserves careful, sharp-tool handling.
Seasonal movement at a glance
Width change for sitka spruce across a typical indoor year — 6% moisture content in the heated winter to 12% in a humid summer:
| Board width | Flatsawn | Quartersawn |
|---|---|---|
| 6″ | 3/32″ (0.096″) | 1/16″ (0.055″) |
| 12″ | 3/16″ (0.193″) | 1/8″ (0.111″) |
| 24″ | 3/8″ (0.386″) | 7/32″ (0.221″) |
| 36″ | 19/32″ (0.579″) | 11/32″ (0.332″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to sitka spruce:
Typical swings:
Sitka Spruce questions
How much does sitka spruce move with the seasons?
A 12″-wide flatsawn sitka spruce board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 7.5% and radial 4.3% (green to ovendry) — a moderate-movement wood.
How hard is sitka spruce?
Sitka Spruce rates about 510 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 28 lb/ft³ at indoor moisture levels.
Is sitka spruce good for wide panels and tabletops?
Yes, with normal precautions: its 1.7:1 tangential-to-radial ratio is moderate. Still fasten solid tops so they can move across their width.
Similar species
Baldcypress · Eastern Hemlock · Black Spruce · Grand Fir · Red Spruce · White Fir
Shrinkage, specific gravity, and hardness from the Wood Handbook, FPL-GTR-282 (2021 edition), USDA Forest Products Laboratory (public domain). Values are species averages — individual boards vary with growth conditions and how they were dried.