What is CDX plywood?

Author: Robbie Sanford  |  Last update: Saturday, May 16, 2026

CDX Plywood is used primarily by contractors to build exterior walls and roofs. CDX plywood has one side veneer grade “C” and one side veneer grade “D”. The two are bonded together with glue which can withstand a little moisture. The APA would recognize CDX Grade Plywood as C-D Exposure 1 plywood.

What is the difference between CDX plywood and regular plywood?

CDX-grade plywood is an inexpensive plywood material, which is made of the two lowest grades, C and D. The X signifies that this material can withstand some exposure to moisture. CDX is oftentimes used for creating work tables and storage units.

Is CDX or OSB better?

OSB can withstand moisture for a longer period because of its gapless structure and the presence of resin inside, but it may change shape with time and exposure to moisture. CDX has low resistance to moisture, however, treated CDX is better, more durable and has improved resistance to termites and rot.

What are the disadvantages of CDX plywood?

Disadvantages of CDX:
  • Not available in large panels.
  • Not durable in terms of water resistance.
  • More expensive than OSB.

Is CDX plywood waterproof?

As mentioned above, the X in CDX stands for exposure. This means that the plywood allows being exposed to moisture, but just for a limited period of time A prolonged exposure will lead to water damage. But, there is an exception to pressure-treated CDX; they can withstand extreme moisture without getting water damaged.

What Is The True Difference Between Oriented Strandboard and CDX Plywood?

What happens if CDX plywood gets wet?

CDX plywood is built to handle some water but is not completely waterproof. It tolerates temporary moisture without serious issues like warping or rotting. It usually manages to bounce back to its original form once it dries out. But it's best to try to avoid staying wet too long.

What type of plywood is best for outdoor use?

Pressure-treated plywood resists rot and insect damage. This damage resistance makes pressure-treated plywood the best choice for exterior projects.

Is CDX OK for subfloor?

CDX plywood is the most common plywood used for subflooring. It is usually more affordable because it is rougher and has more imperfections than other types of plywood. However, since subflooring is almost always covered and rarely visible, the way it looks should not matter.

What is the strongest most durable plywood?

Strongest Plywood Types
  • Marine Plywood. ○ The undisputed champion of strength, marine plywood is specifically designed for extreme durability and moisture resistance. ...
  • Aircraft Plywood. ...
  • Baltic Birch Plywood. ...
  • Structural Plywood.

What are the four types of plywood?

Keep reading to know all the important information about the different types of plywood in the Indian market and their possible applications, to make a wise choice:
  • TYPES OF PLYWOOD IN INDIA: ...
  • Hardwood Plywood- ...
  • Softwood Plywood- ...
  • Sanded Plywood- ...
  • Structural Plywood- ...
  • Decorative plywood- ...
  • Blockboard plywood-

What is the best plywood for subflooring?

Thickness and Grade: The standard subfloor thickness is 3/4 inch. This thickness provides sufficient strength and rigidity to prevent sagging between floor joists. The grade of plywood is also crucial. For subfloors, CDX plywood is often recommended.

Where to use CDX plywood?

Exterior Use: CDX plywood is commonly used for exterior sheathing, roof decking, and wall cladding due to its moisture resistance and durability. Concrete Formwork: Its smooth surface makes CDX plywood suitable for creating formwork for pouring concrete.

Can you use 1/2 inch plywood for a roof?

Typically, half-inch plywood or ¾ inch plywood is the best for roof sheathing. This provides a solid foundation for your shingles while not overloading the decking with heavy wood.

What is the most expensive plywood?

A-grade plywood is the most expensive option because it has a smooth, sanded finish that is free of knots or defects.

What are the three grades of plywood?

Typical applications include signs and non-structural claddings. Exterior plywood is manufactured with a higher quality(A, B, or S grade) face with a reduced quality (C or D grade) back. Exterior plywoods possess either a permanent Type A bond or a less durable Type B bond.

Is 23/32 the same as 3/4?

23/32 inches is slightly less than 3/4 inches but more than 5/8 inches.

What is the weakest plywood?

Plywood comes in either grade A, grade B, grade C, grade D, grade CDX, or grade BCX. As a general statement, board quality goes from A as the best to D as the worst. Furthermore, plywood will sometimes come with a double grade, such as A-B or B-B. In these cases, each grade represents one of the two sides of the panel.

What is as strong as plywood but cheaper?

OSB, which retains much of its structural advantages, is considered a more economical alternative to plywood.

What is the most waterproof plywood?

Marine-grade plywood can be used as waterproof flooring and plywood cladding for spas and gyms. One of the most common uses of marine plywood is boat building. People use it to make different parts of the boat such as the hull. They take advantage of the plywood's excellent pliability and water-resistant properties.

What is better, OSB or CDX?

OSB is much more waterproof than plywood and CDX plywood. The glue and resin that is mixed in with the wood chips makes it much less permeable, so OSB holds up longer in harsher conditions. That is why OSB is sometimes used to secure houses when a hurricane draws near.

Can CDX plywood get wet?

Roof sheathing

In this case, plywood CDX has the durability and water resistance to make it suitable for exterior applications. Additionally, because it is waterproof, CDX will dry very quickly and lose water over time, which helps it return to its original size.

What is another name for CDX plywood?

CDX plywood has one side veneer grade “C” and one side veneer grade “D”. The two are bonded together with glue which can withstand a little moisture. The APA would recognize CDX Grade Plywood as C-D Exposure 1 plywood.

How do you waterproof CDX plywood?

To waterproof plywood, use epoxy, waterproof paint, oil, varnish, latex, or PVA. These sealants come in paint-on or spray forms and bond easily to wood. Simply sand the surface, apply the sealant, and allow it to dry.

Which is stronger, OSB or plywood?

Strength. OSB and plywood are very similar in terms of strength, but plywood is stiffer than OSB by a factor of approximately 10%. This doesn't cause much of a difference, but nails are screws are more likely to remain in place over time than they are in OSB.

Can you use CDX plywood outside?

Moisture Resistance: The “X” in CDX indicates the use of exterior-grade adhesive, which is designed to withstand moisture and resist delamination. While CDX plywood is not completely waterproof, it performs well in environments where it may be exposed to intermittent moisture.

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