Douglas-fir (Coast) (Pseudotsuga menziesii) in numbers: hardness, weight, strength, shrinkage, movement and decay resistance, taken from the tables of the USDA Forest Products Laboratory’s Wood Handbook, followed by what the wood is like to work and what it is used for. The values are averages from small, clear, straight-grained test specimens; real boards with knots, sloping grain or a different moisture content will differ.
| Property | Douglas-fir (Coast) |
|---|---|
| Janka side hardness, 12% moisture | 710 lbf (3,158 N) |
| Janka side hardness, green | 500 lbf |
| Hardness rank | harder than 62 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 33.6 lb/ft³ (538 kg/m³) |
| Weight per board foot (12%) | 2.80 lb |
| Specific gravity (ovendry weight, green volume) | 0.45 |
| Specific gravity at 12% moisture | 0.48 |
| Bending strength (modulus of rupture), 12% | 12,400 psi |
| Stiffness (modulus of elasticity), 12% | 1.95 million psi |
| Crushing strength (compression parallel to grain), 12% | 7,230 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 4.8% / 7.6% / 12.4% |
| Tangential / radial shrinkage ratio | 1.58 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00165 / 0.00267 |
| Impact bending (drop height to failure), 12% | 31 in. |
| Heartwood decay resistance | moderately resistant |
The species in this group
Lumber is often sold under a group name. These are the species the Wood Handbook reports for this group, with the same properties side by side.
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Crushing (psi) | Shrink T/R (%) | Decay resistance |
|---|---|---|---|---|---|---|---|
| Douglas-fir (Coast) Pseudotsuga menziesii | 710 | 33.6 | 12,400 | 1.95 | 7,230 | 7.6 / 4.8 | moderately resistant |
| Douglas-fir (Interior west) Pseudotsuga menziesii | 660 | 35.0 | 12,600 | 1.83 | 7,430 | 7.5 / 4.8 | moderately resistant |
| Douglas-fir (Interior north) Pseudotsuga menziesii | 600 | 33.6 | 13,100 | 1.79 | 6,900 | 6.9 / 3.8 | moderately resistant |
| Douglas-fir (Interior south) Pseudotsuga menziesii | 510 | 32.2 | 11,900 | 1.49 | 6,230 | — | moderately resistant |
What it is
Douglas-fir (Pseudotsuga menziesii) ranges from the Rocky Mountains to the Pacific Coast and from Mexico to central British Columbia. Despite the name it is not a true fir. The Handbook splits its data by region: Coast (Oregon and Washington west of the Cascade summit), Interior West, Interior North and Interior South. Wood from young, fast-growing trees has reddish heartwood (sold as red-fir); very narrow-ringed old-growth heartwood can be yellowish brown (yellow-fir).
Working properties
The wood of Douglas-fir varies widely in weight and strength, which is why it is graded for structural use. In the tables below, coast Douglas-fir is the stiffest of the four regional types (1.95 million psi), while the interior north type is slightly stronger in bending. It is moderately resistant to decay, so exposed outdoor work normally uses treated lumber or a durable species.
Weight and density
At 12% moisture content douglas-fir (coast) weighs about 33.6 lb per cubic foot, so one board foot (144 cubic inches) weighs about 2.80 lb. An 8 ft board of actual size 3/4 × 5-1/2 in. (a 1×6) holds 0.229 cubic feet and weighs about 7.7 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 9.8 lb. Green wood is much heavier because of the water it holds.
Density here is ovendry weight plus 12% water, divided by volume at 12% moisture content (Wood Handbook Eq. 4-12: density = specific gravity at 12% × 62.43 lb/ft³ × 1.12).
Wood movement
The Wood Handbook gives dimensional change coefficients for each species: the fraction of its width a board gains or loses for every 1% change in moisture content, between about 6% and 14%. For douglas-fir (coast) they are 0.00267 across a flatsawn face (tangential) and 0.00165 across a quartersawn face (radial).
Worked example: a flatsawn board 7-1/4 in. wide (a nominal 1×8) that goes from 6% moisture content in a heated winter house to 12% in a humid summer changes width by 7.25 × 0.00267 × 6 = 0.116 in. (about 1/8 in.). The same board quartersawn moves 0.072 in. (about 1/16 in.). Allow for this in panels, tabletops and floors; the wood movement calculator works it out for any size and moisture range.
How it compares
| Species | Janka (lbf) | Density (lb/ft³) | Bending (psi) | Stiffness (Mpsi) | Tangential shrink (%) | Decay resistance |
|---|---|---|---|---|---|---|
| Douglas-fir (Coast) | 710 | 33.6 | 12,400 | 1.95 | 7.6 | moderately resistant |
| Loblolly pine | 690 | 35.7 | 12,800 | 1.79 | 7.4 | slightly or nonresistant |
| Western hemlock | 540 | 31.5 | 11,300 | 1.63 | 7.8 | slightly or nonresistant |
| Western larch | 830 | 36.4 | 13,000 | 1.87 | 9.1 | moderately resistant |
| Eastern white pine | 380 | 24.5 | 8,600 | 1.24 | 6.1 | moderately resistant (old growth only); otherwise slightly or nonresistant |
| Western redcedar | 350 | 22.4 | 7,500 | 1.11 | 5.0 | resistant |
Uses
Mostly building and construction: framing lumber, timbers, laminated beams, plywood and engineered wood products, piles and marine fendering. Also doors, sashes, millwork, crossties, poles, flooring and boats.
Frequently asked questions
How strong is Douglas-fir?
Clear coast Douglas-fir at 12% moisture content averages 12,400 psi in bending and 7,230 psi in compression parallel to the grain. These are small clear-specimen values, not design values for graded lumber.
How hard is Douglas-fir?
Coast Douglas-fir averages 710 lbf on the Janka test, harder than most pines and spruces but much softer than oak.
Can I use these numbers to size a beam?
No. Structural design uses grade-specific design values that account for knots and other defects. Size beams and joists from your local building code or have a licensed professional do it.
Sources
- USDA Forest Products Laboratory. Wood Handbook: Wood as an Engineering Material. General Technical Report FPL-GTR-190, 2010. Chapter 2 (species descriptions), Chapter 4 (Tables 4-3, 4-4 shrinkage; Eq. 4-7, 4-9, 4-12 density), Chapter 5 (Tables 5-3b, 5-5b strength and hardness), Chapter 13 (Table 13-5 dimensional change coefficients), Chapter 14 (Table 14-1 decay resistance)
- USDA Forest Products Laboratory. Wood Handbook, 2021 edition (FPL-GTR-282)
Last reviewed: 22 October 2026. Numbers are generated from our parsed copy of the Handbook tables, so every page uses the same data. Values marked * are estimates computed with the Handbook’s own equations. Spotted an error? Please let us know.