Wood species
Incense cedar wood
Incense cedar is a softwood (Calocedrus decurrens). At 12% moisture content it has a Janka hardness of 470 lbf (2,091 N) and it weighs about 26 lb/ft³ (414 kg/m³), 2.2 lb (0.98 kg) per board foot.
Also called: incense-cedar.
Key numbers
- Janka hardness, 12% MC
- 470 lbf (2,091 N)
- Green: 390 lbf (1,735 N)
- Weight at 12% MC
- 26 lb/ft³ (414 kg/m³)
- 2.2 lb per board foot
- Specific gravity (oven-dry weight)
- 0.37 at 12% MC volume
- 0.35 on green volume
- Shrinkage, green to oven-dry
- 5.2% tangential
- Radial 3.3%, volumetric 7.7%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; incense cedar's density is worked from its specific gravity with the Handbook's own equation.
How much incense cedar moves
A 12 in wide flatsawn board of incense-cedar that goes from 6% to 12% moisture content swells about 0.13 in (about 1/8 in, 3.3 mm). Quartersawn, the same board moves about 0.08 in (about 3/32 in, 2 mm). Flatsawn faces move 1.6 times as much as quartersawn ones, because the wood shrinks 5.2% around the growth rings but only 3.3% across them.
Worked with the Wood Handbook's dimensional change coefficients for incense-cedar (Table 13-5: 0.0018 tangential, 0.00112 radial per 1% change in moisture content), which hold between 6% and 14%. Individual boards vary: the Handbook gives shrinkage a coefficient of variation of about 15% (p. 4-11).
Color, grain and working
- Color
- White or cream sapwood; light brown heartwood, often tinged red.
- Grain and texture
- Fine and uniform, with a spicy smell. Much of it is “pecky” from decay pockets that stop once dried.
- Working and character
- Light, soft and fairly weak, with low shrinkage; it dries easily with little checking or warping.
- Uses
- Pencils and venetian blinds from the best grades; chests, toys, fence posts and rough construction.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-13.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of incense-cedar tested by the Forest Products Laboratory (Wood Handbook Table 5-3b). Knots and cross grain make lumber weaker than these clear samples (Handbook Chapter 5).
| Property | Green | 12% MC |
|---|---|---|
| Bending strength (MOR) | 6,200 psi (43 MPa) | 8,000 psi (55 MPa) |
| Stiffness (MOE) | 840,000 psi (5.8 GPa) | 1,040,000 psi (7.2 GPa) |
| Crushing strength (compression parallel to grain) | 3,150 psi (22 MPa) | 5,200 psi (36 MPa) |
| Compression perpendicular to grain | 370 psi (3 MPa) | 590 psi (4 MPa) |
| Shear parallel to grain | 830 psi (6 MPa) | 880 psi (6 MPa) |
| Tension perpendicular to grain | 280 psi (2 MPa) | 270 psi (2 MPa) |
A dash means the Handbook prints no value; none is filled in.
Dust and health
- Wood dust is classed as carcinogenic to humans (Group 1) by the International Agency for Research on Cancer, chiefly for cancers of the nose and sinuses.
- NIOSH recommends keeping wood dust exposure to 1 mg/m³ of total dust, as quoted in OSHA's sawmill guidance.
This is what the named authorities publish, not medical advice.
Compare with
Why these numbers
Why these numbers?
The situation
The USDA Forest Products Laboratory measured incense-cedar at 470 lbf of side hardness at 12% moisture content, on clear, straight-grained samples (Wood Handbook Table 5-3b).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
What that means
Side hardness (Janka) is the load needed to press a 0.444 in (11.28 mm) steel ball halfway into the wood across the grain; a higher number dents less (Handbook p. 5-5).
One source: USDA Forest Products Laboratory, the authority for species properties it measured , sources [1]
So
Density at 12% is water's density × specific gravity × (1 + 0.12) (Handbook Eq. 4-14): 62.43 × 0.37 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 26 lb/ft³, or 2.2 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources