Tamarack wood movement, board-foot & weight calculator
- Janka
- 590lbf
- Density
- 37lb/ft³
- T/R ratio
- 2
- Spec. gravity
- 0.53
Tamarack is a North American softwood. It has a Janka side hardness of 590 lbf, a specific gravity of 0.53, and an air-dry density near 37 lb/ft³ (593 kg/m³) (mechanical values at 12% moisture content). It shrinks 7.4% tangentially and 3.7% radially from green to oven-dry (T/R ratio 2), so a 12-inch flatsawn board moves about 0.18 in (≈ 3/16 in) across a 6-point moisture swing (about 6%→12% MC).
Compute Tamarack: movement, weight & board footage
Every number below is worked from Tamarack's own shrinkage and density figures, not looked up from a table — change the width, moisture swing, or board size in the calculators linked alongside.
Cross-grain movement by board width
| Board width | Flatsawn (tangential) | Quartersawn (radial) |
|---|---|---|
| 2″ | 0.03″ (≈ 1/32 in) | 0.015″ (≈ 0 in) |
| 3″ | 0.044″ (≈ 1/32 in) | 0.022″ (≈ 1/32 in) |
| 4″ | 0.059″ (≈ 1/16 in) | 0.03″ (≈ 1/32 in) |
| 6″ | 0.089″ (≈ 3/32 in) | 0.044″ (≈ 1/32 in) |
| 8″ | 0.118″ (≈ 1/8 in) | 0.059″ (≈ 1/16 in) |
| 10″ | 0.148″ (≈ 5/32 in) | 0.074″ (≈ 1/16 in) |
| 12″ | 0.178″ (≈ 3/16 in) | 0.089″ (≈ 3/32 in) |
| 16″ | 0.237″ (≈ 1/4 in) | 0.118″ (≈ 1/8 in) |
Need a different width or moisture swing? Run the movement calculator preloaded with Tamarack. At a T/R ratio of 2, Tamarack is moderately unstable — it moves substantially more tangentially than radially, so flatsawn stock is noticeably cup-prone and quartersawn stock is worth the extra cost in wide panels.
Board footage & weight, standard sizes
| Nominal size × length | Board feet | Weight |
|---|---|---|
| 1×4 × 8′ | 2.67 bd ft | 8.2 lb |
| 1×6 × 8′ | 4 bd ft | 12.3 lb |
| 1×8 × 8′ | 5.33 bd ft | 16.4 lb |
| 1×10 × 8′ | 6.67 bd ft | 20.6 lb |
| 1×12 × 8′ | 8 bd ft | 24.7 lb |
| 2×4 × 8′ | 5.33 bd ft | 16.4 lb |
| 2×6 × 8′ | 8 bd ft | 24.7 lb |
| 2×8 × 8′ | 10.67 bd ft | 32.9 lb |
Different length or size? Run the board foot calculator or the weight calculator, both preloaded with Tamarack.
Seasonal movement by city
| City | Driest month (EMC) | Most-humid month (EMC) | EMC swing | 12″ board movement |
|---|---|---|---|---|
| Phoenix, AZ | Jun · 4.4% | Dec · 9% | 4.6 pts | 0.136″ (≈ 1/8 in) |
| Chicago, IL | May · 12.3% | Dec · 15.1% | 2.8 pts | 0.083″ (≈ 3/32 in) |
| Miami, FL | Apr · 12.2% | Sep · 14.4% | 2.2 pts | 0.065″ (≈ 1/16 in) |
| Boston, MA | Apr · 11.5% | Sep · 12.8% | 1.3 pts | 0.038″ (≈ 1/32 in) |
| Denver, CO | Jul · 8% | Dec · 10.5% | 2.5 pts | 0.074″ (≈ 1/16 in) |
| Seattle, WA | Jul · 12% | Dec · 16.9% | 4.9 pts | 0.145″ (≈ 5/32 in) |
Driven by Tamarack's tangential shrinkage of 7.4%. These are outdoor equilibrium-moisture figures, so they are an upper bound — a climate-controlled interior swings less. How this is calculated.
How Tamarack compares
Ranked against the 196 species in the Wood Handbook tables this site carries.
- Hardness: at 590 lbf, Tamarack is harder than 27% of the 157 species with a Janka figure.
- Weight: at 37 lb/ft³ it is heavier than 50% of the 170 species measured — an 8-foot 1×6 board weighs about 12.3 lb.
- Stability: its T/R ratio of 2 is more even than 32% of the 196 species here — as humidity changes, 68% of them hold their shape more evenly.
See Tamarack plotted against every species we carry: the full Janka hardness chart and the full density chart .
Species with a similar working profile
Closest matches on hardness, weight and stability together — useful when Tamarack is unavailable or priced out.
- Sweetgum is a common substitute for Tamarack : 44% harder, about the same weight, and similarly stable in service.
- Red Pine is a common substitute for Tamarack : nearly identical hardness, 13% lighter, and similarly stable in service.
- Red Maple is a common substitute for Tamarack : 61% harder, about the same weight, and similarly stable in service.
- Hackberry is a common substitute for Tamarack : 49% harder, about the same weight, and similarly stable in service.
About Tamarack
Tamarack (Larix laricina), also known as eastern larch and locally as hackmatack, is a small to medium tree with a straight, round, slightly tapered trunk. It grows from Maine to Minnesota, with the bulk of the stand in the Great Lake States. The heartwood of tamarack is yellowish brown to russet brown. The sapwood is whitish, generally less than 3 cm (1 in.) wide. The wood is coarse in texture, without odor or taste, and the transition from earlywood to latewood is abrupt. The wood is intermediate in weight and in most mechanical properties. Tamarack is used principally for pulpwood, lumber, railroad crossties, mine timbers, fuel, fence posts, and poles. Lumber is used for framing material, tank construction, and boxes, pallets, and crates. The production of tamarack lumber has declined in recent years.
Durability & sustainability
Decay resistance: the Wood Handbook rates Tamarack heartwood moderately resistant to fungal decay . Ratings are for heartwood only and the table's own note cautions that resistance varies substantially within a species; treat this as a general indicator, not a guarantee, especially for ground contact. Wood Handbook, Chapter 14: Biodeterioration of Wood (Arango, Lebow, Glaeser), USDA Forest Products Laboratory, FPL-GTR-282 (2021), Table 14-1. Public domain.
CITES status: not listed on any CITES Appendix — no international-trade restriction applies to Tamarack.
Properties
| Specific gravity | 0.53 |
|---|---|
| Janka hardness (side) | 590 lbf |
| Density (air-dry, 12% MC) | 37 lb/ft³ (593 kg/m³) ovendry-weight basis: 33.1 lb/ft³ |
| Weight per board foot (air-dry) | 3.08 lb |
| Radial shrinkage (green→oven-dry) | 3.7% |
| Tangential shrinkage (green→oven-dry) | 7.4% |
| Volumetric shrinkage (green→oven-dry) | 13.6% |
| T/R ratio (stability indicator) | 2 |
Shrinkage is total green-to-oven-dry (Table 4-3); strength values are at 12% MC. Full bases and the derivation formulas are on the methodology page.
Data: USDA Forest Products Laboratory, Wood Handbook FPL-GTR-282 (2021), public domain.