The three softwoods comprising the principal species in the Spruce-Pine-Fir (SPF) species group share many common characteristics and properties, as well as the same native habitat in the montane, boreal and subalpine forest regions of British Columbia (B.C.) and Alberta. White Spruce, Lodgepole Pine and Alpine Fir are all trees of medium size, averaging 30 metres in height and up to 80 centimetres in diameter. They are hardy trees, relatively slow-growing and yield high-grade timber with small, sound, tight knots. Well suited to the cold winters and hot summers that characterize the continental climate of their northern forest area, trees of the SPF group are the most abundant softwoods in Canada and the most commercially important. Forest reserves are estimated at more than 500 million cubic metres, and reforestation efforts already in place assure excellent continuity of supply over the long term.

Common exterior uses

Spruce-Pine-Fir's strength, light weight, ease of handling and good working properties have made it a popular wood for framing applications in all types of construction. Strong, stiff and stable, SPF is well-known and highly regarded not only in North America, but also in Europe and Japan. Readily available in a wide range of sizes and lengths, including finger jointed lengths up to 12 metres, it is an extremely versatile lumber for residential, commercial, industrial and agricultural buildings. SPF is a particular favourite with house builders, who appreciate its high structural performance as well as its pine appearance. The prefabrication industry is also a major user of SPF because of the wood's strength, dimensional stability and superior gluing properties. Manufacturers of modular houses, trusses and other structural components, regularly specify kiln-dried SPF as a wood they can rely on for consistent quality and ready availability in precise dimensions.

Appearances and properties

In contrast with other commercial softwoods, SPF is a distinctly white wood, with very little colour variation between springwood and summerwood. The wood has a bright, clean appearance, ranging in colour from white to pale yellow, with a pine straight grain and smooth texture. SPF has a high strength to weight ratio and is well known for its outstanding working properties. It takes and holds nails exceptionally well and is easily worked with hand power tools. It has good gluing, painting and staining properties. Lumber of this species group is seasoned uniformly in dry kilns to a moisture content of 19 percent or less. Kiln drying inhibits natural staining of the wood, improves its strength and stiffness, enhances its appearance, and also increases its resistance to decay and attack by insects. The drying process also improves the wood's dimensional stability, finishing qualities and thermal resistance while at the same time reducing shrinkage, warping and checking in storage.

Physical properties

Spruce Pine Fir
Stiffness / MOE (MPa) Air dry 10000 10900 10200
Strength / MOR (MPa) Air dry 63 76 56
Density (KG/M3) Air dry 380 430 351
Compression Parallel (Mpa) Air dry 36.9 43.2 35.4
Shear (Mpa) Air dry 6.79 8.54 6.74
Shrinkage (air dried-12%) Tangential/radial ratio 2.2 1.4 2.8

Working Properties - White Spruce

Machining:

Process: Planing

Performance: Very good

Comments: Good planing quality; recommended planer settings: 12° or 20° hook angle and 20 kmpi (knife marks per inch)

Process: Shaping

Performance: Good

Comments: Good shaping quality

Process: Sanding

Performance: Very good

Fastening:

Process: Screwing

Performance: Good

Comments: Very good resistance to splitting

Process: Nail retention

Performance: Good

Comments: Very good resistance to splitting

Process: Gluing

Performance: Average

Finishing:

Process: Staining

Performance: Good

Comments: Good staining properties, a smooth finish is achieved; a natural finish (clear coat) or a light stain looks the best

Process: Painting

Performance: Average

Drying:

Process: Ease of drying

Performance: Good

Comments: Spruce dries faster than pine and is not adversely affected by severe high-temperature schedules

Durability:

Process: Natural decay resistance

Performance: Poor

Comments: Not appropriate for prolonged outdoor exposure

Process: Treatability

Performance: Good

Comments: Can be improved by incising

Working properties- Lodgepole pine

Machining:

Process: Planing

Performance: Excellent

Comments: Recommended planer settings: 20° hook angle and 8, 12, or 16 kmpi (knife marks per inch)

Process: Shaping

Performance: Good

Process: Sanding

Performance: Good

Fastening:

Process: Screwing

Performance: Average

Process: Nail retention

Performance: Average

Process: Gluing

Performance: Easy

Drying:

Process: Ease of drying

Performance: Good

Comments: Few defects expected except in the most extreme cases

Durablity:

Process: Natural decay resistance

Performance: Poor

Comments: Not appropriate for prolonged outdoor exposure

Process: Treatability

Performance: Good

Comments: Can be improved by incising

Working properties - Alpine Fir

Machining:

Process: Planing

Performance: Good

Comments: Recommended planer settings: 20 hook angle and 20 kmpi (knife marks per inch)

Process: Sawing

Performance: Good

Process: Shaping

Performance: Good

Process: Sanding

Performance:Good

Fastening:

Process: Screwing

Performance: Average

Process: Nail retention

Performance: Average

Process: Gluing

Performance: Easy

Comments: Bonds very easily with adhesives of a wide range of properties and under a wide range of bonding conditions

Process: Staining

Performance: Easy

Comments: Smooth finish with little texture, dark stain can highlight prominent wild grain; recommended: light-coloured stains with low penetration power will produce a more even colour

Finishing

Process: Painting

Performance: Average to good

Drying:

Process: Ease of drying

Performance: Good

Comments: Few defects expected except in the most extreme cases

Durability:

Process: Natural decay resistance

Performance: Fair

Comments: Not appropriate for prolonged outdoor exposure

Process: Treatability

Performance: Poor

Comments: Can be improved by incising