What Is CDX Plywood? | All You Need To Know About CDX

Last Updated on September 23, 2021 by Kimberly Crawford

Plywoods are available in a wide range of grades, and their quality may immediately be determined. A CDX plywood is the lowest splinter class, which persons in the building sector widely use. It’s much thicker, making it perfect as a substrate of other materials or foundation. Moreover, the cost of CDX splinter is reduced in enormous volumes. It means the exposed plywood of class C and D.

Choosing the correct type of wood for house assembling projects is an ultimate necessity because the kind of wood can affect the long-term maintenance, durability, and performance to be anticipated.

Various kinds of wood can provide multiple cons and pros. That being said, CDX plywood is probably the best choice for a DIY plan. But probably they are not ideal for other house-building activities.

Whether the individual is making a backing outer siding or a tiny bookcase, the kind of house building project will make a huge contrast as to whether or not CDX plywoods are good enough for the project at hand.

CDX: Class C to D Exposed Plywoods

Contractors and employees broadly use CDX Plywood for outside walls and roofs. On one side of the CDX plywood, the “C” side furnace is utilised. Both are connected by a sticky component that can withstand a tiny volume of water. The American Plywood Association (APA) recognises all CDX-graded plain wood with C and D exposure.

CDX Plywood is a plate wood with a grade C in the front and a D in the backside of the plate wood. This type of plate wood is utilised primarily for outside purposes.

A CDX splinter box gives a more resistant and sophisticated resin level (specially designed to withstand water).

The Understanding Of CDX Plywood

cdx plywood

The Understanding Of CDX Plywood is quite essential.

Based on the system, CDX plywood retains a “C” class and a “D” class surface on each side. The “C” side is the noticeable side, while the side ‘D’ remains hidden.

It is essential to comprehend the face flanks of the plywood, even if it will be synopsised in the future. While creating the top with CDX plywood, side C should be confronting upside (to be covered later) if the D-side is facing downwards; it is presumed to be recognised in the loft.

The impression of this is not essential in this case; utility counts most. One can find CDX plywood in the markets in several heights, shapes, sizes such as 3, 5, 7,9, etc.

This plywood can have a consistent span beginning from 1/4 inches to 11/4 inches.

Other accessible density ranges are – 3/8 inches, 1/2, 5/8, and 3/4 inches in nearly all the shops.

Exterior plywood, where CDX plywood is encompassed, is commonly formulated with pines or firs.

In both cases, the conifers do not shed their pointers in the plunge. In opposition to hardwoods, which have left to fall off each year, they accumulate faster.

The Letter ‘X’ in CDX Plywood

In CDX, “X” refers to the type of glue used for connecting the flaking veneers in the production. Some individuals believe that “X” represents the outside, but is not valid.

In fact, the letter “X” denotes exposure that means that the surface is hard enough to stand a little hydration, but it is brief only. For the panel to stand water for a prolonged period, something weather-resistant, such bricks, side rails or shingle should be used to protect the panels.

How Is CDX Plywood Formulated?

Manufactures build any plywood from multiple plies compressed tightly together to generate a more substantial piece of plywood.

Exterior plywood is typically available in plies of three, five, seven, and nine, with the most decreased quantities are signifying the highest class plywood.

By compressing a more significant number of these plates together, they make CDX, making wood much tighter and thicker.

CDX plywood is the gift of humanity, made of a mixture of at least three wooden sheets that are consolidated using a specific glue. In addition, the bond maintains them long intact. Unlike solid wood that can grow or contract due to outside influences, splinter has the characteristic of preserving similar measures throughout its life expectancy.

CDX plywoods can speak a lot about itself and about how it is made easy by its name. The term CDX is an amalgamation of ranking that offers details as to the standard and built of the exterior plywood.

 The standard of the wood can be checked out based upon the durability, colour, splinter, knots, and so much more. These characteristics are evaluated and then authorised ranking whether it’s A, B, C or D.

 Precisely like in University, a is the most premium ranking that stands for high quality; on the other hand, D is the Rock bottom of ranking that stands for a standard level.

 Sheets of plywood that classify as A or B are most likely to be the more expensive pieces. Where the level C for level d plywood sheets are more budget-friendly and gimmicky in standard, this makes it a more low-cost option.

The X in this kind ofplywood indicates how the multiple veneers of plywood layers are pasted together. The standard of adhesive used in the exterior plywood will be less or more sensitive to harm due to the vulnerability.

When we come to CDX plywood, the x at the endpoints out exposure; this means even though CDX plywood is only a bit water-resistant, it is not at all waterproof.

 That means the CDX plywood can only resist a small number of witnesses over a short period before it starts showing symptoms of decline.

 When individuals are layering it all together, they have to keep in mind that CDX plywood is produced by time up at least 3 to 4 layers of planks together.

 So the end product eventually characterises a different exterior grade plywood layer on each side. One piece is rated C, and another piece is rated D.

 Show the Siri X marks the standard of the layering on every side. One D veneer glued with one C veneer and tied Together by a glue that only offers a specific amount of liability to witness.

In the process of CDX plywood glueing together, makers correctly place the green wooden component of the plywood sheet so that they are lined up in a way that diffuses contraction.

 Sometimes poor-quality planks are utilised for inner veneers to set aside better quality layers for the exterior part. No matter what, CDX plywood rates as an affordable and convenient sheet of planks collection of many layers. When someone analyses this exterior grade, plywood initially has a lot of components to think of.

Why CDX Plywood Is Available At A Reasonable Price?

To lower the contraction degree, companies put the wood grain in every layer such that its next layer produces a straight angle. When every ply becomes perpendicular to its external or internal sheet, the wood does not develop on either side, possibly influencing its initial measurements.

At the beginning of the production process, splinted wood manufacturers collect logs from diverse outside sources. Subsequently, the quality and species are separated. The layered construction approach also represents a tremendous advantage for perfect wood floors or sheaths in the recesses at a reasonable price.

Usage Of CDX Plywood

The excavated CDX splinter sheets can indeed be avoided by exposure to high moist conditions or even rain without influencing the integrity of the construction.

In addition, this sort of plywood absorbs water, broadening somewhat all the time.

It is therefore not water-resistant. But it goes back to its standard size once it dries up.

People use CDX often as a lavatory or kitchen floor—especially on ceramic tile floors.

CDX is nearly 10% louder than OSB, operates as a subfloor regularly because of its economy (when it crosses over equally spaced beams, rafters, or joists).

This enhanced durability(in particular) helps with the use of CDX splices as subfloors.

Exterior Uses

  1. Roof sheathing is one of CDX’s most popular external applications. This plate is generally used by several techniques, which make it exceedingly robust and waterproof. As regards external applications, this makes it a good choice of material.

In addition to that, CDX will dry quickly and lose water over time when water is consumed (since it is not waterproof).

  1. Since the aesthetic value in crates and boxes is not a huge matter, CDX is one of the few desirable solutions for crates. Its size stability and water damage resistance is also an added advantage, which is their robust character.

Internal Uses

  1. The CDX plywood may not be the most excellent solution for racks. This does not, however, depend on its quality but its design, and so nothing gets lost when it is used to construct a frame in the garage or the workplace.
  2. The incredible strength of CDX is always helpful in lessening bowing and flexing.
  3. The CDX plywood is mainly utilised in lavatories and kitchens to delivering an over the floor with ceramic floor finishing.  It is also easier to get and in enough quantities due to its inexpensive nature. CDX is maybe the most cost-effective and available on the market for latewood.

For How Long CDX Plywood Can Be Exposed?

CDX plywood isn’t weatherproof ideally. Prolonged or frequent exposure to rain or snow will compromise the integrity of the material.

If you’re in the middle of a project and you’re in winter, that’s another matter. It would help if you also offered some protection, especially for exposed sheathing roofs, for every exposed CDX plywood.

Merely the feeling on the top is enough to preserve it till the temperature warms.


 House owners who think of using CDX plywood for their upcoming Constructions should acknowledge that this plywood by no means is a fit for large-scale exposure of the components.

 The number one reason being it is not waterproof. Snow and rain can appear as an alarming danger to the purity of the construction made by CDX plywood.

 With that being said, this plywood can hold out against remote vulnerabilities to witness involving snow and rain

Exterior Plywoods

cdx plywood use

Exterior grade plywood is Most widely used in the building industry for its structural characteristics and pricing point. It is generally built from softwoods such as Douglas Fir or Pine.

For fitting the veneer layers together, a substantial external (waterproof) glue is employed. The relatively high surfaces are polished on both surfaces and are occasionally known as refinished or sanded panels.

How Is Exterior Plywood Made?

Outer splinter is a weather-resistant splinter used primarily for outdoor use. It is comprised of numerous wood veneer layers, which are joined with phenolic resin.

The glue solidifies to form a crystalline material that makes the floorboard wet for more resistance.

Manufacturers employed hoop pine wood in the fabrication of external plywood. Spruce, mahogany, dogs fir, birch, oak, and maple Are other plywood components of exterior plywood.

Usage of Exterior Plywood

For non-structural uses, exterior plywood is used by most manufacturers. You use the splice qualities to achieve an appealing finish of high quality.

However, the exterior plywood is not just confined to external use. Some constructors also utilized the plate indoors. These include storage and cooling.

External plywood also works as a floor. Its waterproof nature does not enable moisture from the surface or below to enter the base. These are widely used in sinks, benchtops, and kitchen cabinets.

Related: 16+ Different Types Of Flooring With Pictures (Kitchen, Bathroom, Living Room,…)


CDX plywood has a lot of pros and cons. This is why house owners should be sure to think of the strict requirements of their construction to decide if CDX plywood is a good fit for the structure. They can also take professional help to figure it out. 

It is beautiful plywood for builders and homeowners who hunt for long-lasting and budget-friendly resources.