⅝ in. CDX Fir Sheathing, 4 ft. x 8 ft.

Plywood manufactured under U.S. Product Standard PS 1-83 may be made from over 70 species of wood. These species are divided according to strength and stiffness properties into five groups. Group 1 species are the strongest and the stiffest, Group 2 the next strongest and stiffest, and so on. Douglas Fir species are listed under both Group 1 and Group 2, depending on growing location. Ring's End carries Douglas Fir plywood sheathing to provide construction projects some of the best products in the industry. - ⅝ in. CDX Fir Sheathing, 4 ft. x 8 ft.