ine or F
ir--an acronym used in the specification of construction grade lumber.
Four species, White Spruce (Picea glauca), Engelmann Spruce (Piceaengelmanni), Lodgepole Pine (Pinus contorta), and Alpine Fir (Abieslaciocarpa) comprise the spruce-pine-fir species group. All yield high grade timber with relatively small, sound tight knots. Lumber produced from spruce-pine-fir Species is marketed together as SPF.
SPF lumber is a distinctly white wood, with very little color variation between springwood and summerwood. The wood has a bright, clean appearance, ranging in color from white to pale yellow, with a fine straight grain and smooth texture.