Western redcedar (Thuja plicata) 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 | Western redcedar |
|---|---|
| Janka side hardness, 12% moisture | 350 lbf (1,557 N) |
| Janka side hardness, green | 260 lbf |
| Hardness rank | harder than 2 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 22.4 lb/ft³ (358 kg/m³) |
| Weight per board foot (12%) | 1.86 lb |
| Specific gravity (ovendry weight, green volume) | 0.31 |
| Specific gravity at 12% moisture | 0.32 |
| Bending strength (modulus of rupture), 12% | 7,500 psi |
| Stiffness (modulus of elasticity), 12% | 1.11 million psi |
| Crushing strength (compression parallel to grain), 12% | 4,560 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 2.4% / 5.0% / 6.8% |
| Tangential / radial shrinkage ratio | 2.08 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00111 / 0.00234 |
| Impact bending (drop height to failure), 12% | 17 in. |
| Heartwood decay resistance | 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 |
|---|---|---|---|---|---|---|---|
| Western redcedar Thuja plicata | 350 | 22.4 | 7,500 | 1.11 | 4,560 | 5.0 / 2.4 | resistant |
| Eastern redcedar Juniperus virginiana | — | 32.9 | 8,800 | 0.88 | 6,020 | 4.7 / 3.1 | resistant |
| Incense cedar Calocedrus decurrens | 470 | 25.9 | 8,000 | 1.04 | 5,200 | 5.2 / 3.3 | resistant |
| Yellow-cedar (Alaska) Chamaecyparis nootkatensis | 580 | 30.8 | 11,100 | 1.42 | 6,310 | 6.0 / 2.8 | resistant |
| Atlantic white cedar Chamaecyparis thyoides | 350 | 22.4 | 6,800 | 0.93 | 4,700 | 5.4 / 2.9 | resistant |
| Northern white-cedar Thuja occidentalis | 320 | 21.7 | 6,500 | 0.8 | 3,960 | 4.9 / 2.2 | resistant |
| Port-Orford cedar Chamaecyparis lawsoniana | 630 | 30.1 | 12,700 | 1.7 | 6,250 | 6.9 / 4.6 | resistant |
What it is
Western redcedar (Thuja plicata) grows in the Pacific Northwest and along the coast to Alaska. Most of the lumber comes from Washington, then Oregon, Idaho and Montana. The heartwood is reddish or pinkish brown to dull brown and the narrow sapwood, often 1 in. or less, is nearly white.
Working properties
The wood is generally straight grained with a uniform but rather coarse texture, and it has very low shrinkage. It is lightweight, moderately soft, low in strength as a beam or post and low in shock resistance. The heartwood is resistant to decay, which, with its stability, is why it is used for siding, shingles and decking. Only the heartwood is durable: sapwood should not be used where decay is a risk.
Weight and density
At 12% moisture content western redcedar weighs about 22.4 lb per cubic foot, so one board foot (144 cubic inches) weighs about 1.86 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 5.1 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 6.5 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 western redcedar they are 0.00234 across a flatsawn face (tangential) and 0.00111 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 × 0.00234 × 6 = 0.102 in. (about 3/32 in.). The same board quartersawn moves 0.048 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 |
|---|---|---|---|---|---|---|
| Western redcedar | 350 | 22.4 | 7,500 | 1.11 | 5.0 | resistant |
| Redwood (old-growth) | 480 | 28.0 | 10,000 | 1.34 | 4.4 | resistant |
| Redwood (young-growth) | 420 | 24.5 | 7,900 | 1.1 | 4.9 | moderately resistant |
| Baldcypress | 510 | 32.2 | 10,600 | 1.44 | — | resistant (old growth); moderately resistant (young growth) |
| Eastern white pine | 380 | 24.5 | 8,600 | 1.24 | 6.1 | moderately resistant (old growth only); otherwise slightly or nonresistant |
| Douglas-fir (Coast) | 710 | 33.6 | 12,400 | 1.95 | 7.6 | moderately resistant |
Uses
Shingles, siding, decking, poles, posts and piles; boats; interior woodwork, sashes and doors; boxes and crates.
Frequently asked questions
Is cedar rot resistant?
The heartwood of western redcedar and of the other cedars in the table is in the Wood Handbook’s resistant decay class. Sapwood is not. For ground contact, use treated wood or a very resistant species.
How much does western red cedar weigh?
About 22.4 lb per cubic foot at 12% moisture content, or 1.86 lb per board foot, one of the lightest commercial softwoods.
Why does cedar make good siding?
It shrinks and swells very little: 5.0% tangential shrinkage from green to ovendry, and about 0.234% width change per 1% change in moisture content for a flatsawn board.
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.