WOOD SPECIES · Softwood
Western red cedar: density, weight and properties
Thuja plicata
Western red cedar (Thuja plicata) averages 358.4 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
- 358.4 kg/m³Specific gravity 0.32 (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)
- 0.31
- Janka side hardness at 12%
- 1,600 N (≈ 360 lbf)
- Bending strength (modulus of rupture)
- 51.7 MPa
- Stiffness (modulus of elasticity)
- 7,700 MPa
- Compression parallel to grain
- 31.4 MPa
- Tangential shrinkage, green to oven-dry
- 5.0%
- Radial shrinkage, green to oven-dry
- 2.4%
- Volumetric shrinkage, green to oven-dry
- 6.8%
- Fibre saturation point
- 30%Not measured: Wood Handbook default
Weight at 12% moisture content
Volume × 358.4 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 | 358.4 kg |
| 1 board foot | 12 × 12 × 1 in | 0.85 kg |
| 1×4 board, 8 ft | 3/4 × 3 1/2 in actual × 8 ft | 1.48 kg |
| 1×6 board, 8 ft | 3/4 × 5 1/2 in actual × 8 ft | 2.33 kg |
| 2×4 board, 8 ft | 1 1/2 × 3 1/2 in actual × 8 ft | 2.96 kg |
| 2×6 board, 10 ft | 1 1/2 × 5 1/2 in actual × 10 ft | 5.81 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 | 1.4 mm (0.056 in) | 0.7 mm (0.027 in) |
| 6 percentage points | 2.9 mm (0.113 in) | 1.4 mm (0.054 in) |
Wood movement across the grain · Moisture content and acclimatising wood
Natural durability
The Wood Handbook groups the heartwood as resistant to decay (Table 14-1). Resistant heartwood generally gives satisfactory service above ground where decay can occur; ground contact calls for very resistant or treated wood.
Working and finishing
Lightweight, moderately soft and low in strength, with very low shrinkage; generally straight grained with a uniform but rather coarse texture. It is used for siding, decking, shingles, boats, sashes and doors (Wood Handbook, chapter 2).
Softwoods have no vessels (Wood Handbook, chapter 16), so pore filling is not part of finishing them.
Typical uses
- Cladding and siding
- Decking
- Interior joinery and millwork
- Boatbuilding
- Doors and sashes
Calculate with this material
Species with similar density
- Norway spruce 450 kg/m³
- Poplar 450 kg/m³
- Cedro (Spanish cedar) 460 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.