Spruce

1.5-2 usd/kg
Circularity potential
Very high
Strength
Medium
Production energy
Ultra low
Stiffness
Medium
Embodied CO2
Ultra low
Density
Ultra low

Spruce is a light coloured softwood, with little contrast between heartwood and sapwood. Unlike pine, it has almost no odour and the wood has a uniform, relatively knot-free appearance. It is used in light construction work, engineered wood (glulam and plywood), wood fibre products and pulp (paper making). General purpose timber is relatively inexpensive.

Spruce is prized for its superior acoustic properties. It has uniform properties and shrinks little after seasoning. These qualities are utilised in quarter-sawn soundboards for musical instruments, such as violin, cello and piano. The highest quality musical instruments are produced from spruce that has been specifically selected before felling and air dried for a decade or more. These are some of the most expensive timbers available.


Sustainability concerns
Non-renewable ingredients
Raw material generates polluting by-products
Low circularity potential
Potentially toxic in use


Laminated veneer lumber (LVL) is a structural lumber produced from wood cut into thin layers (rotary cut veneers) and bonded together with high strength adhesive. The majority of the layers run along the length of the wood’s profile, to optimise strength to weight, with just a few running perpendicular to provide some resistance to twisting. Veneer thickness is typically around 3 mm. LVL sheets and lumber range from 21-75 mm thick, 40 mm to 1.5 m wide, and up to 25 m long. Thicker parts are made possible by gluing multiple layers of LVL together (GLVL). A range of woods are suitable, but spruce and pine are the most popular as a result of their favourable balance of cost, weight and mechanical performance.

Applications include beams and headers, lintels, joists, rafters and ridge beams, truss chords, studs and columns, wall framework, portal frames and components for modular pre-fabricated roof, floor and wall elements. In addition, sheets (much like plywood), can be used in roof, floor and wall construction; doors and windows; and concrete formwork.


Design properties
Cost usd/kg
1.5-2.5
Embodied energy MJ/kg
8-11
Carbon footprint kgCO2e/kg
0.6-0.9
Density kg/m3
400-500
Tensile modulus GPa
8.96–19.24
Tensile strength MPa
35-52
Modulus of rupture MPa
33.78–86.18
Hardness Mohs
1
Janka hardness kN
2.3-3.1
Thermal conductivity W/mK
0.13
Temperature min-max °C
-40 to 150
Thermal
insulator
Electrical
insulator