Tsuga heterophylla
DISTRIBUTION
Northwest coast of North America
TREE SIZE
165-200 ft (50-60 m) tall, 3-5 ft (1-1.5 m) trunk diameter
AVERAGE DRIED WEIGHT
29 lbs/ft 3 (465 kg/m 3 )
SPECIFIC GRAVITY (Basic, 12% MC)
.37, .47
JANKA HARDNESS
540 lb f (2,400 N)
MODULUS OF RUPTURE
11,300 lb f /in 2 (77.9 MPa)
ELASTIC MODULUS
1,630,000 lb f /in 2 (11.24 GPa)
CRUSHING STRENGTH
7,200 lb f /in 2 (37.3 MPa)
SHRINKAGE
Radial: 4.2%, Tangential: 7.8%, Volumetric: 12.4%, T/R Ratio: 1.9
COLOR/APPEARANCE
Heartwood is light reddish brown. Sapwood may be slightly lighter in color but usually isn’t distinguished from the heartwood. Occasionally contains dark streaks caused by bark maggots. The conspicuous growth rings can exhibit interesting grain patterns on flatsawn surfaces.
GRAIN/TEXTURE
Grain is generally straight, with a coarse, uneven texture.
ENDGRAIN
Resin canals absent; earlywood to latewood transition usually gradual, color contrast fairly high; tracheid diameter medium-large.
ROT RESISTANCE
Rated as non-durable regarding decay resistance, and also susceptible to insect attack.
WORKABILITY
Overall working properties are good, but because of the disparity between the soft earlywood and the hard latewood, sanding can create dips and uneven surfaces. Glues, stains, and finishes well.
ODOR
No characteristic odor.
ALLERGIES/TOXICITY
Western Hemlock has been reported to cause skin and respiratory irritation, as well as runny nose. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.
PRICING/AVAILABILITY
Western Hemlock is one of the two primary commercial species of hemlock harvested in North America—with the other being Eastern Hemlock (Tsuga canadensis). Western Hemlock is used as construction lumber and is commonly grouped together with other species of fir and hemlock and sold under the more generic label “HEM-FIR.” Expect prices to be moderate for a domestic softwood.
SUSTAINABILITY
This wood species is not listed in the CITES Appendices, and is reported by the IUCN as being a species of least concern.
COMMON USES
Boxes, pallets, crates, plywood, framing, and other construction purposes.
COMMENTS
Western Hemlock is the largest of the hemlocks, and is one of the most valuable sources of exportable lumber for Canada; the species is also the state tree of Washington. When compared to Eastern Hemlock (Tsuga canadensis), Western Hemlock generally has narrower growth rings, though both species can have tightly spaced growth rings.