What is SPF Lumber?

Long, geometrically stacked lumber
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If you walk through the lumber section of your local home center and take a look at most of the construction-grade lumber found there, you may be looking at wood categorized in the industry as SPF lumber. The SPF stamp is an indication of the lumber's species. It is an acronym that stands for spruce, pine and fir, referring to any of these types of coniferous trees grown and harvested in various regions of North America, primarily Canada and some northern regions of the U.S. The SPF classification originated in the Canadian lumber industry, but the SPF lumber sold in stores and lumberyards may also include lumber from trees grown in the U.S.

The spruce, pine, and fir species comprising the SPF category all produce high-grade timber with relatively small, sound tight knots and a color that ranges from white to pale yellow. At a lumber yard or home center, the inventory of SPF framing lumber can include any one of these three types of trees, and it may contain one or more species within the type (for example, several species of spruce might be found in the store's stock of 2 x 4s sold under the same grade).

SPF Species

The SPF lumber sold at a particular retailer is usually from tree species grown relatively near the outlet, since this minimizes transportation costs. These species are usually categorized as eastern and western species of conifers. 

Eastern species:

  • Black spruce (Picea mariana)
  • Red spruce (Picea rubens)
  • White spruce (Picea glauca)
  • Jack pine (Pinus banksiana)
  • Balsam fir (Abies balsamea)

Western species:

  • White spruce (Picea glauca)
  • Engelmann spruce (Picea engelmanni)
  • Lodgepole pine (Pinus contorta)
  • Alpine fir (Abies lasiocarpa)

Western SPF lumber is usually available in larger sizes than eastern SPF, due to the more favorable climate that creates larger logs.. Eastern SPF trees grow slowly and are more expensive, but they have superior strength.

Lumber that is does not have the SPF species stamp may be stamped "DF-L," standing for Dougas fir and larch, or "Hem-fir," standing for western hemlock and several true fir species. Any of these stamps may be found on lumber used for standard framing construction, depending on where the lumber outlet buys its products from. 

Uses for SPF Lumber

SPF is perfect for residential and commercial framing construction because of its reasonable price and high strength-to-weight ratio. It can also be used for industrial production of:

  • Furniture framing
  • Engineered wood products
  • Concrete formworks
  • Packaging
  • Other re-manufactured products

SPF is used widely in North America for wood-frame construction. Countries in Europe and Asia are also beginning to use SPF when replacing old and damaged housing built by different methods. Wood framing is durable and economical, and construction with wood frames is proving to be a great cost-effective option for building houses, apartments, and commercial buildings. Research and testing also demonstrate that it stands up to tough climates and conditions. The benefits of wood-frame construction include:

  • Dependable grading system: SPF Lumber is graded identically, according to the rules of the National Lumber Grades Authority (NLGA). Agencies inspect the products from all mills regularly to ensure that the grades are accurate.
  • Durability: Wood-frame construction can last as long as a building's occupants need, and many have stood for hundreds of years.
  • Quick construction: Wood-frame construction is speedy– a crew of three can frame one floor per day per unit. SPF also takes paint easily and holds nails well.
  • Affordability: Wood-frame construction is so successful in North America partially because it's so cost-effective.
  • Meeting or exceeding building codes: Research and testing has shown that wood-frame construction meets or surpasses building code requirements for fire safety, strength and sound transmission.

While SPF is typically used in construction, it can also be used in some fine woodworking projects—with certain caveats.