Sitka Spruce

Sitka Spruce (Picea sitchensis)

Common Name(s): Sitka Spruce

Scientific Name: Picea sitchensis

Distribution: Northwestern North America

Tree Size: 160 ft (50 m) tall, 5 ft (1.5 m) trunk diameter

Average Dried Weight: 28 lbs/ft³ (455 kg/m³)

Basic Specific Gravity: .36

Hardness: 510 lb_f (2,270 N)

Rupture Strength: 10,150 lb_f/in² (70,000 kPa)

Elastic Strength: 1,600,000 lb_f/in² (11,030 MPa)

Crushing Strength: 5,610 lb_f/in² (38.7 MPa)

Shrinkage: Radial: 4.3%, Tangential: 7.5%, Volumetric: 11.5%, T/R Ratio: 1.7

Color/Appearance: Can range from a creamy white, to a darker medium brown. Also tends to exhibit a subtle pinkish hue in some instances.

Grain/Pore: Sitka Spruce has a fine, even texture, and a consistently straight grain.

Endgrain: Medium sized resin canals (larger than other spruce), sparse to numerous and variable in distribution; solitary or in tangential groups of several; earlywood to latewood transition gradual, color contrast medium; tracheid diameter medium-large.

Durability: Heartwood is rated as being slightly resistant to non-resistant to decay.

Workability: Easy to work, as long as there are no knots present. Glues and finishes well, though it can give poor (blotchy and inconsistent) results when being stained due to its closed pore structure. A sanding sealer, gel stain, or toner is recommended when coloring Spruce.

Scent: There is no characteristic odor associated with this wood species.

Safety: Although severe reactions are quite uncommon, Spruce in the Picea genus has been reported as a sensitizer. Usually most common reactions simply include skin irritation and/or respiratory disorders. See the articles Wood Allergies and Toxicity and Wood Dust Safety for more information.

Price/Availability: Construction grade spruce is cheap and easy to find. However, old growth and/or quartersawn clear pieces—free from knots—can be more expensive. Quartersawn billets of instrument-grade Sitka Spruce can easily exceed the cost of most all domestic hardwoods in terms of per board-foot cost.

Comments: Sitka Spruce has an outstanding stiffness-to-weight ratio, and is available in large, straight-grained pieces, lending this timber to a wide range of commercial uses.

Common uses include: lumber, boxes/crates, furniture, millwork, aircraft components, musical instrument soundboards, boatbuilding (masts and spars), wind turbine blades, and virtually any application where a wood material with a good strength-to-weight ratio is needed.

Related Species:

Black Spruce (Picea mariana)

Engelmann Spruce (Picea engelmannii)

Norway Spruce (Picea abies)

Red Spruce (Picea rubens)

White Spruce (Picea glauca)