Western larch (Larix occidentalis) 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 larch |
|---|---|
| Janka side hardness, 12% moisture | 830 lbf (3,692 N) |
| Janka side hardness, green | 510 lbf |
| Hardness rank | harder than 71 of the 168 woods with a 12% hardness value in our database |
| Density at 12% moisture | 36.4 lb/ft³ (582 kg/m³) |
| Weight per board foot (12%) | 3.03 lb |
| Specific gravity (ovendry weight, green volume) | 0.48 |
| Specific gravity at 12% moisture | 0.52 |
| Bending strength (modulus of rupture), 12% | 13,000 psi |
| Stiffness (modulus of elasticity), 12% | 1.87 million psi |
| Crushing strength (compression parallel to grain), 12% | 7,620 psi |
| Shrinkage green to ovendry: radial / tangential / volumetric | 4.5% / 9.1% / 14.0% |
| Tangential / radial shrinkage ratio | 2.02 |
| Dimensional change per 1% moisture (radial / tangential) | 0.00155 / 0.00323 |
| Impact bending (drop height to failure), 12% | 35 in. |
| Heartwood decay resistance | moderately 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 larch Larix occidentalis | 830 | 36.4 | 13,000 | 1.87 | 7,620 | 9.1 / 4.5 | moderately resistant |
| Tamarack Larix laricina | 590 | 37.1 | 11,600 | 1.64 | 7,160 | 7.4 / 3.7 | moderately resistant |
What it is
Western larch (Larix occidentalis) grows in western Montana, northern Idaho, northeastern Oregon and on the eastern slope of the Cascade Mountains in Washington. About two-thirds of the lumber is produced in Idaho and Montana and one-third in Oregon and Washington. The heartwood is yellowish brown, and the yellowish white sapwood is generally not more than 1 in. wide.
Its eastern relative, tamarack (L. laricina), is also known as eastern larch and locally as hackmatack. It is a small to medium tree that grows from Maine to Minnesota, with the bulk of the stand in the Great Lake States. Tamarack heartwood is yellowish brown to russet brown, and the whitish sapwood is generally less than 1 in. wide.
Working properties
Western larch is stiff, moderately strong and hard, moderately high in shock resistance and moderately heavy, with moderately high shrinkage (9.1% tangentially from green to ovendry). It is usually straight grained, splits easily and is subject to ring shake; knots are common but generally small and tight. Its properties are similar to those of Douglas-fir, and the two are sometimes sold mixed. Tamarack is coarse in texture and without odor or taste, with an abrupt change from earlywood to latewood, and it is intermediate in weight and in most mechanical properties.
Weight and density
At 12% moisture content western larch weighs about 36.4 lb per cubic foot, so one board foot (144 cubic inches) weighs about 3.03 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 8.3 lb; an 8 ft piece 1-1/2 × 3-1/2 in. (a 2×4 size) weighs about 10.6 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 larch they are 0.00323 across a flatsawn face (tangential) and 0.00155 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 × 0.00323 × 6 = 0.141 in. (about 1/8 in.). The same board quartersawn moves 0.067 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 larch | 830 | 36.4 | 13,000 | 1.87 | 9.1 | moderately resistant |
| Douglas-fir (Coast) | 710 | 33.6 | 12,400 | 1.95 | 7.6 | moderately resistant |
| Loblolly pine | 690 | 35.7 | 12,800 | 1.79 | 7.4 | slightly or nonresistant |
| Western hemlock | 540 | 31.5 | 11,300 | 1.63 | 7.8 | slightly or nonresistant |
| Sitka spruce | 510 | 28.0 | 10,200 | 1.57 | 7.5 | slightly or nonresistant |
| Western redcedar | 350 | 22.4 | 7,500 | 1.11 | 5.0 | resistant |
Uses
Western larch: rough dimension lumber for building construction, small timbers, planks and boards, railroad crossties and mine timbers, piles, poles and posts; high-grade material for interior woodwork, flooring, sashes, doors and ladder stock. Tamarack: pulpwood, lumber, railroad crossties, mine timbers, fuel, fence posts and poles, with lumber for framing, tank construction and boxes, pallets and crates. Tamarack lumber production has declined in recent years.
Frequently asked questions
How hard is western larch?
Western larch averages 830 lbf (3,692 N) on the Janka test at 12% moisture content, harder than coast Douglas-fir (710 lbf). Tamarack averages 590 lbf.
Is larch the same as Douglas-fir?
No, but the Handbook says their properties are similar and the two are sometimes sold mixed. Western larch is a little denser than coast Douglas-fir (36.4 against 33.6 lb/ft³) and harder.
Is larch rot resistant?
Moderately. Table 14-1 of the Wood Handbook puts western larch and tamarack heartwood in the moderately resistant class, below the cedars and old-growth redwood. The Handbook says heartwood in this class usually needs some form of preservative treatment where there is a decay hazard.
What is tamarack?
Tamarack (Larix laricina), also called eastern larch and locally hackmatack, is the larch of the Northeast and the Great Lake States. The Handbook describes its wood as intermediate in weight and in most mechanical properties.
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: 24 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.