Sheathing grades
Sheathing grades of plywood are structural-use panels for roofs, subfloors, and walls. These include
- C-C
- C-C Structural I
- C-D
- C-D Structural I
(from Voluntary Product Standard, PS 1-09, Structural Plywood section 5.8.5 and table 6)
Sheathing panels are unsanded.
(from Panel Design Specification)
Face and Back Veneer Grades of Sanded Panels
Face and back plies made from A- and B-grade veneers are sanded, but the back ply of a sanded panel can be made from C- or D-grade veneer and left unsanded. C-C Plugged and C-D Plugged panels are touch sanded.