What is CDX Plywood?

What is CDX Plywood?

Although CDX plywood's quality is low-grade, it definitely happens to be the strongest of all in the construction field. So, what is with the abbreviation of CDX? What exactly do these letters mean? Let's find out.
As we already know, plywood are thin sheets of wood veneer which are glued together with linking plies and have a quality which is resistant to breaking, twisting, or any sort of cracking. Plywood are generally high-strength sheet materials used for utmost ruggedness in constructing buildings and homes. Also, different varieties of plywood are available for a number of applications. When you shop for these at a hardwood store, you will find different grading systems, which use alphabets like A, B, C, and D. Each letter has its own explanation. CDX is an economically graded plywood. The quality of this plywood is low but the strength it exhibits is powerful.


C - one side of the sheet board is C grade―the average surface.
D - the other side of the sheet board is the D grade―having small holes and patches.
X - The exterior glue that bonds the sheet board together.

The term CDX is basically not the name of the plywood grade, but the abbreviation of C-D Exposure 1 plywood. Herein, the letters C and D denote the quality of the surfaces (both front and back). That is, C and D describe the two sides of the plywood sheet. So one side of the plywood is C-rated and the other side is D-rated. And the letter 'X' denotes that the glue which is exploited in the plywood is an exterior glue. But that doesn't make it an overall extended plywood. The plywood is made out of waterproof glue and is treated under intense pressure. Such a treatment enhances every layer of wood veneer to compress vertically against the previous one and make it even more stronger. It is employed in roof sheathing, on walls and sub floors, shingles and roofing felt, etc.

In the grading system of plywood, the letter A is considered to have the best quality―without blemishes, flaws, or sanding in the sheets. Whereas, the last grade, i.e, the D grade of plywood, contains maximum amount of flaws and blemishes in its making. Thus, although CDX plywood is low in grade and is not very pretty to look at, it is a strong, rugged sheathing material, preferred in rough home construction projects.

More on CDX Plywood
  • This plywood, when used in constructing wooden items, is very easy to spot and differentiate. It is thick in size and contains fillers, patches, knots, some football-shaped shallow holes, and indentations on both sides. Though such quality will make you think twice, it's priced very low as compared to other high-quality plywood.
  • Also, this material chiefly happens to be the foundation or base material for building roofs. It's known that the quality of CDX plywood is extremely durable, and hence, it is ideal as a building material for a roof base. They are also used in many art and craft projects.
  • Generally, this plywood is not polished, but is sanded well. Hence, both the sides of the plywood are rough enough, containing good amount of knots and patches in its sheets.
  • Another thing about CDX plywood is, although the letter 'X' in the abbreviated term stands for exterior glue, it isn't entirely true! Basically, the letter denotes exposure, which means that this plywood is strong enough to resist a bit of a moisture level in the sheets, but not for long.
It's only because of the superb built of this plywood, which makes it so strong and inviolable, that it has picked up so much popularity in the interior decoration field.