EPICEA - PICEA EXCELSA LINK   English: German: Italian: Spanish: Norway spruce - European Spruce Fichte Abete rosso Picéa - Abeto rojo   ANATOMY   Timber very white and shiny, sometimes brilliant on a planed surface No differentiation sapwood / heartwood The growth rings are visible without being too marked Presence of fine hardly visible longitudinal resinous canals The grain is remarkably straight, punctuated by frequent small knots   DURABILITY   Spruce is a timber termed "non durable", it offers little natural resistance to attack by fungi and insects. It is essential to treat framework timber with an insecticide and fungicide product to give it a protection of treatment type risk class 2.   DENSITY   this is dependent on the source and the growth conditions   Density at 15 % moisture content (kg/m3)   Majority of the timber Limit value according to source Spruce 450 - 550 kg/m3 350 - 600 kg/m3   SHRINKAGE   The retractability coefficient gives, as a percentage, the dimensional variation for a variation of one per cent of moisture content.   Tangential coefficient of retractability Radial coefficient of retractability Unit volume coefficient of retractability   (t) in % (r) in % (v) in % Spruce 0.25 to 0.35 0.10 to 0.15 0.40 to 0.45   THERMAL CONDUCTIVITY   This is the heat flow per m2 through one metre of thickness of the material, for a difference of one degree between the two faces of the material.   Density in kg/m3 Thermal conductivity in W/m°C   350 to 500 0.12 Spruce 500 to 600 0.15   ACOUSTIC BEHAVIOUR   The speed of propagation of sound in the timber at 15% moisture content     Propagation of sound in m/sec Spruce longitudinally 4,700 to 5,000 transversally 1,000 to 1,100   BEHAVIOUR TO FIRE   Classification of materials M0 = incombustible M1 = not flammable M2 = burns with difficulty M3 = average flammability M4 = burns easily M5 = highly inflammable Spruce: thickness greater than / equal to 18 mm = class M3 thickness less than 18 mm = class M4   MECHANICAL CHARACTERISTICS   Visual classification: ST - III: type of use - traditional framework ST - II: type of use - industrial framework, truss Timber at a moisture content of 12% Strength properties:   ST-III ST-II Bending 8.0 Mpa 10.5 Mpa Compression parallel 8.0 Mpa 9.0 Mpa Tension parallel 5.0 Mpa 6.0 Mpa Longitudinal shear 0.8 Mpa 1.1 Mpa Perpendicular compression 2.0 Mpa 2.3 Mpa Perpendicular tension 0.15 Mpa 0.15 Mpa Conventional deformation modulus:   ST-III ST-II Shear 550 Mpa 690 Mpa Longitudinal, shear force included 10,000 Mpa 11,000 Mpa 1 Mpa = 1 MegaPascal 1 Mpa = approx. 10 kg/cm²