Larch
The densest of the common softwoods, with better natural durability than most conifers. Used for cladding, decking and fence posts where treated timber is not wanted.
Properties
- Family
- Wood
- Category
- wood
- Species
- Larix spp.
- Density
- 0.58 g/cm³ · 580 kg/m³
Densityhow larch compares
Wood propertiesUSDA clear-wood values at 12% moisture content
- Species measured
- Western larch (Larix occidentalis)
- Specific gravity
- 0.52
- Janka side hardness
- 830 lbf · 3,692 N
- Modulus of rupture
- 13,000 psi · 89.6 MPa
- Modulus of elasticity
- 1.87 ×10⁶ psi · 12.89 GPa
- Shrinkage, green to oven-dry
- 4.5% radial · 9.1% tangential · 14% volumetric
Source: USDA Forest Service, Wood Handbook — Wood as an Engineering Material (FPL-GTR-190, 2010), Table 5–3b, for clear straight-grained specimens at 12% moisture content. The grey figures are converted at 1 lbf = 4.448 N, 1 psi = 6.895 kPa and 1 GPa = 145,038 psi; the inch-pound numbers are the published ones. Specific gravity is oven-dry mass over volume at 12% moisture content, so it sits about 12% below the working density at the top of this page (0.52 × 1.12 ≈ 0.58 g/cm³). The two come from different sampling programmes, so a few species differ by more than that.
Applicationswhere larch is normally specified
Appearance & workabilitytrade experience, not measured values
- Origin
- Western North America; the European larch is a separate species
- Appearance
- Yellowish to reddish-brown with a bold, resinous grain
- Working
- Denser and harder than the other softwoods here. The resin can gum blades, and the timber is more durable than most.
Unlike the USDA figures above, these lines are not measurements: they carry no units and no single source. They describe how the timber is generally found to behave rather than what it is guaranteed to do — read them as the consensus of the trade, not as a specification.
Practical notes
- Density is for air-dried stock at about 12% moisture content
- Denser and harder than pine — pre-drill near board ends
- Naturally durable but not in permanent ground contact
Lumber sizeswhat larch weighs in each nominal size
Lumber size databaseDressed sizes are the same for every species — a 2x4 is 1-1/2 x 3-1/2 in in oak as much as in spruce. What changes is the weight, and that is derived here from larch's density of 0.58 g/cm³.
Tools used on itmatched on the wood family, not on this page
All toolsWhich tools work a material is a property of the family (Wood), not of the individual species — so this list is the same on every wood page, and changes when the tool data changes rather than when this paragraph does.
Used in these projectsbuilds whose bill of materials calls for it
All projectsFrequently asked questionsthe questions this page answers about Larch
How hard is Larch?
Janka hardness is 830 lbf — the force needed to push a steel ball halfway into the wood. Higher is harder; this is the number quoted when a wood is specified for floors, worktops or butcher blocks.
How dense is Larch?
Density is 0.58 g/cm³, and the USDA table gives a specific gravity of 0.52.
How much does Larch move when it dries?
Green to oven-dry it shrinks 14% by volume — 4.5% radially and 9.1% tangentially. Movement across the grain is what opens joints, so a species that moves a lot wants room to move.
What is Larch used for?
Typical uses are Cladding, Decking, Fence posts and Outdoor structures.
How does Larch work with hand and machine tools?
Denser and harder than the other softwoods here. The resin can gum blades, and the timber is more durable than most.