Spruce Pine-Fir (SPF)
The SPF lumber is a combination of Canadian Spruces, Pines and Firs growing in different regions of the country. All yield high grade timber with relatively small, sound tight knots.
Part of a larger group of tree species known as softwoods, in the wood industry. Spruce-Pine-Fir refers to Canadian woods of similar characteristics that have been grouped for production and marketing. Mainly used to make dimensional lumber for home building and panel (such as Plywood and Oriented Strand Board [OSB] ), the SPF species have moderate strength, worked easily, take paint readily, and hold nails well. They are White to Pale Yellow in color.
SPF is easily worked, glues well, is average in paint holding ability, and takes nails and screws satisfactorily. It is not very durable and is difficult to penetrate with preservatives.