How to Install CDX Plywood Sheeting
Plywood has a grading system allowing for its usage. CDX plywood is an exterior grade plywood, the "X" referring to waterproof glue and exterior usage. The A, B, C and D classifications determine the face quality of the plywood. Premium grade plywood is marked with an A, with quality declining in order with B, C and D. Therefore, the distinction "CDX" means that the plywood has one side with some defects and one side with many defects. The defects are only on a surface level and do not compromise the plywood. CDX plywood is used for the "sheer" in home-building, the first layer after the house is framed.
Place a 1/2-inch flat piece of wood at the base of the studs on the concrete floor of the exterior wall. This will be the spacer to keep the CDX from touching the concrete.
Stand a sheet of CDX plywood on top of the 1/2-inch spacer, flush against the studs. Start from one corner and flush the outside edge of the plywood with the outside edge of the stud. The other side of the plywood should terminate exactly half-way down the center of another stud.
Shoot a staple through the plywood into the studs on both top corners. Stand another piece of plywood up beside the first piece on top of the spacer. The two pieces of plywood should both be centered on the same stud. Shoot staples into the top corners.
Shoot staples around the perimeter of both pieces 8 inches apart. Using the exposed part of the stud at the bottom, mark all of the studs locations with a lumber crayon. Use a straightedge to run a pencil line up the plywood to mark the studs' vertical locations.
Shoot staples into all studs 8 inches apart. Pull out the spacers and move them down to the next section. Stand up two more pieces of plywood on the spacers and continue shooting staples until you come to the end of the wall. Measure, mark, and cut the plywood with a circular saw where needed to complete the wall.
Things You Will Need
- Wood spacers, 1/2-by-1 1/4-by-96 inches
- Staple gun
- Staples 1/2 inch crown, 1 1/4 inch leg
- Straightedge, 48 inch
- Circular saw
- If the studs installed are not perfectly square and vertical, shoot staples into the top corners and then tap two pieces at a time sideways with a hammer until the sides of the plywood align with the studs, and then finish stapling the perimeter.
- CDX has one good side and one bad side. Make sure to place the bad side against the studs.