Spruce

Spruce

Picea abies
Other names: Whitewood, Norway spruce

General description

The species is widely distributed throughout continental Europe and is a timber tree of major economic importance. The large tree usually has a straight, cylindrical trunk and grows to a height of about 30 m (up to 55 m), with a large diameter of about 60 cm (up to 1,5 m).

Wood description

The colours range from creamy white to light yellow and to red-brown. Heartwood is not distinct from sapwood. Spruce is straight-grained with thin and regular texture. Resin canals are rather common. The wood is soft, low in weight and has medium density. The strength properties are good.
Sawing and machining is easy, also assembling. Spruce has a slight tendency to split when nailed.

Common uses

The typical end-uses for spruce wood are for structural end uses, indoors and outdoors, thus it is the most important building and construction timber in Europe. It is also used for decorative plywood, decorative veneer, domestic flooring, factory flooring, general carpentry, interior construction, joinery (external). Spruce wood from Central and Eastern Europe shows exceptional resonance qualities and is used for musical instruments like sound boards of pianos and bellies of violins and guitars.

Physical characteristics
Density (at 12 % moisture content) 441 kg⁄m3
Total longitudinal shrinkage 0.3 %
Total radial shrinkage 3.6 %
Total tangential shrinkage 7.8 %
Equilibrium moisture content  
(20° C⁄ 37 % rel. humidity) 7.0 %
(20° C⁄ 83 % rel. humidity) 16.4 %
Mechanical characteristics
Modulus of elasticity under bending 12500 N⁄mm2
Modulus of rupture under bending 77 N⁄mm2
Tension strength 95 N⁄mm2
Compression strength 44 N⁄mm2
Brinell hardness perpendicular to the fibres 44 N⁄mm2
Janka Hardness 1.6 kN
Nail withdrawal strength in N per mm depth and mm diameter 5.5 N⁄mm2
Natural durability and treatability (according to en 350-2)
Fungi Class 4 –poorly durable
Dry wood borers susceptible
Termites Class S susceptible
Treatability 3-4 poorly or not permeable

Natural durability is based on mature heartwood. Sapwood must always be considered as non durable against wood destroying agents.