Wood species
Eastern red cedar wood
Eastern red cedar is a softwood (Juniperus virginiana). Its Janka hardness is 650 lbf (2,891 N) green; the Handbook prints no dry value and it weighs about 33 lb/ft³ (526 kg/m³), 2.7 lb (1.24 kg) per board foot.
Also called: eastern redcedar, redcedar.
Key numbers
- Janka hardness, 12% MC
- Not measured
- Green: 650 lbf (2,891 N)
- Weight at 12% MC
- 33 lb/ft³ (526 kg/m³)
- 2.7 lb per board foot
- Specific gravity (oven-dry weight)
- 0.47 at 12% MC volume
- 0.44 on green volume
- Shrinkage, green to oven-dry
- 4.7% tangential
- Radial 3.1%, volumetric 7.8%
One source: USDA Forest Products Laboratory, the authority for species properties it measured
Why: Measured by the USDA Forest Products Laboratory; eastern red cedar's density is worked from its specific gravity with the Handbook's own equation.
How much eastern red cedar moves
A 12 in wide flatsawn board of eastern redcedar that goes from 6% to 12% moisture content swells about 0.12 in (about 1/8 in, 3 mm). Quartersawn, the same board moves about 0.08 in (about 1/16 in, 1.9 mm). Flatsawn faces move 1.5 times as much as quartersawn ones, because the wood shrinks 4.7% around the growth rings but only 3.1% across them.
Worked with the Wood Handbook's dimensional change coefficients for eastern redcedar (Table 13-5: 0.00162 tangential, 0.00106 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
- Bright or dull red heartwood and narrow, nearly white sapwood.
- Grain and texture
- Fine and uniform, usually with many small knots.
- Working and character
- Moderately heavy and hard, low in stiffness, with very low shrinkage, stable once dry, and very decay-resistant heartwood.
- Uses
- Chests, wardrobes and closet lining; fence posts, pencils and small boats.
The Handbook gives eastern redcedar’s side hardness only for green wood; its 12% MC value is printed as “—”.
Adapted in our own words from the Wood Handbook, Chapter 2, p. 2-17.
Strength
Bending strength is the modulus of rupture (MOR); stiffness is the modulus of elasticity (MOE). Clear, straight-grained samples of eastern redcedar 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) | 7,000 psi (48 MPa) | 8,800 psi (61 MPa) |
| Stiffness (MOE) | 650,000 psi (4.5 GPa) | 880,000 psi (6.1 GPa) |
| Crushing strength (compression parallel to grain) | 3,570 psi (25 MPa) | 6,020 psi (42 MPa) |
| Compression perpendicular to grain | 700 psi (5 MPa) | 920 psi (6 MPa) |
| Shear parallel to grain | 1,010 psi (7 MPa) | — |
| Tension perpendicular to grain | 330 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 Wood Handbook prints eastern redcedar's side hardness as 650 lbf for green wood; dry it is not measured (Table 5-3b shows "—"), so no dry value is given here.
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 × 0.47 × 1.12.
Arithmetic: exact by definition , sources [1]
The number
About 33 lb/ft³, or 2.7 lb per board foot (1/12 ft³), at 12% moisture content.
Arithmetic: exact by definition
Sources