Douglas-Fir
Pseudotsuga menziesii · softwood · Western North America · moderate movement
- Janka hardness 660 lbfred oak ≈ 1,290 lbf
- Density ≈ 34 lb/ft³specific gravity 0.48 at 12% MC
- Shrinkage — tangential 7.6%flatsawn width, green → ovendry
- Shrinkage — radial 4.8%quartersawn width
- T/R ratio 1.6 : 1higher = more cupping in flatsawn stock
Shop notes The framing benchmark, and vertical-grain (quartersawn) fir is fine interior trim in its own right. Hard latewood, soft earlywood — sand with a block or the surface ripples.
Seasonal movement at a glance
Width change for douglas-fir 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″ (0.098″) | 1/16″ (0.062″) |
| 12″ | 3/16″ (0.195″) | 1/8″ (0.123″) |
| 24″ | 13/32″ (0.391″) | 1/4″ (0.247″) |
| 36″ | 19/32″ (0.586″) | 3/8″ (0.370″) |
Run your own numbers
Different width, different climate swing — the calculator below is preset to douglas-fir:
Typical swings:
Douglas-Fir questions
How much does douglas-fir move with the seasons?
A 12″-wide flatsawn douglas-fir board moves about 3/16″ across a typical indoor swing from 6% to 12% moisture content; quartersawn, about 1/8″. Its tangential shrinkage is 7.6% and radial 4.8% (green to ovendry) — a moderate-movement wood.
How hard is douglas-fir?
Douglas-Fir rates about 660 lbf on the Janka scale — soft enough to dent in daily use (red oak is roughly 1,290 lbf). Density runs about 34 lb/ft³ at indoor moisture levels.
Is douglas-fir good for wide panels and tabletops?
Yes, with normal precautions: its 1.6:1 tangential-to-radial ratio is unusually balanced, so panels stay flatter than most. Still fasten solid tops so they can move across their width.
Similar species
Loblolly Pine (Southern Yellow) · Shortleaf Pine · Port-Orford-Cedar · Tamarack · Alaska Yellow-Cedar · Jack Pine
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.