WOOD SPECIES · Softwood
Douglas-fir: density, weight and properties
Pseudotsuga menziesii
Douglas-fir (Pseudotsuga menziesii) averages 537.6 kg/m³ at 12% moisture content, according to the USDA Wood Handbook. The figures below are averages for clear, mature wood; individual boards vary with origin, growth and moisture.
Key figures
- Density at 12% moisture
- 537.6 kg/m³Specific gravity 0.48 (oven-dry mass, volume at 12%) × 1.12 × 1,000 kg/m³, Wood Handbook Eq. 4-14
- Basic specific gravity (oven-dry mass, green volume)
- 0.45
- Janka side hardness at 12%
- 3,200 N (≈ 719 lbf)
- Bending strength (modulus of rupture)
- 85 MPa
- Stiffness (modulus of elasticity)
- 13,400 MPa
- Compression parallel to grain
- 49.9 MPa
- Tangential shrinkage, green to oven-dry
- 7.6%
- Radial shrinkage, green to oven-dry
- 4.8%
- Volumetric shrinkage, green to oven-dry
- 12.4%
- Fibre saturation point
- 30%Not measured: Wood Handbook default
Weight at 12% moisture content
Volume × 537.6 kg/m³, the same calculation as the weight calculator. Green or wet wood weighs considerably more.
| Piece | Size | Weight |
|---|---|---|
| 1 cubic metre | 1,000 × 1,000 × 1,000 mm | 537.6 kg |
| 1 board foot | 12 × 12 × 1 in | 1.27 kg |
| 1×4 board, 8 ft | 3/4 × 3 1/2 in actual × 8 ft | 2.22 kg |
| 1×6 board, 8 ft | 3/4 × 5 1/2 in actual × 8 ft | 3.49 kg |
| 2×4 board, 8 ft | 1 1/2 × 3 1/2 in actual × 8 ft | 4.44 kg |
| 2×6 board, 10 ft | 1 1/2 × 5 1/2 in actual × 10 ft | 8.72 kg |
Movement across the width
How much a board 11 1/4 in (286 mm) wide changes when its moisture content moves by a few percentage points. The estimate uses the total shrinkage above and a linear relation below the fibre saturation point of 30% (Wood Handbook Eq. 4-9). Flat-sawn boards move with tangential shrinkage, quartersawn boards with radial shrinkage.
| Moisture change | Flat-sawn | Quartersawn |
|---|---|---|
| 3 percentage points | 2.2 mm (0.086 in) | 1.4 mm (0.054 in) |
| 6 percentage points | 4.3 mm (0.171 in) | 2.7 mm (0.108 in) |
Wood movement across the grain · Moisture content and acclimatising wood
Natural durability
The Wood Handbook groups the heartwood as moderately resistant to decay (Table 14-1). Wood in this group usually needs some form of preservative treatment where decay can develop.
Working and finishing
Weight and strength vary widely, so denser wood should be chosen where high strength is needed. Mostly used for building as lumber, plywood and laminated beams, and for sashes, doors and millwork. The figures are for coast Douglas-fir (Wood Handbook, chapter 2 and Table 5-3a).
Softwoods have no vessels (Wood Handbook, chapter 16), so pore filling is not part of finishing them.
Typical uses
- Framing and structural timber
- Plywood
- Doors and sashes
- Glued-laminated timber
- Interior joinery and millwork
Calculate with this material
Species with similar density
- Paraná pine 540 kg/m³
- Scots pine 550 kg/m³
- Black cherry 560 kg/m³
Sources & references
- USDA FPL · Wood Handbook (2021), ch. 5: Mechanical properties of wood
- USDA FPL · Wood Handbook (2021), ch. 4: Moisture relations and physical properties of wood
- USDA FPL · Wood Handbook (2021), ch. 14: Biodeterioration of wood
- USDA FPL · Wood Handbook (2021), ch. 2: Characteristics and availability of commercially important woods
- USDA FPL · Wood Handbook (2021), ch. 16: Finishing of wood
Uses and working notes summarise the cited source. Check the moisture content, grade and origin of the wood you actually buy.