Structural plywood used for sheathing surfaces of a building prior to being covered with other materials such as flooring, siding, or roofing. C/D grade indicates that the face has knots and defects filled in while the reverse side may have some that aren’t filled in. Neither side has been sanded smooth or appearance grade.
A sanded plywood panel with A-grade face, C-grade back and C-grade inner plies bonded with exterior glue. Our AC is solid core for use as underlayment.