Construction Lumber Structural Joists and Planks
Photo (right) of Douglas fir, sawn, unseasoned, mixed grades of No. 1 and No. 2 shown in 6″, 8″ and 10″ widths (NLGA Rules).Photo (left) of Douglas fir sawn, unseasoned, No. 3 grade shown in 6″ and 8″ widths (NLGA Rules).
No. 3 grade permits more imperfections than No. 1 and No. 2.
Note: this type of lumber is available in all species, graded to Canadian or foreign grading rules or to market specifications, kiln dried or unseasoned, in imperial or metric sizes up to 12″ (300mm) squares.