So, you’re ready to start your next project and are thinking of using plywood. While you know about the material in general, you are probably wondering what the right type for your project is. After all, the wide variety of options can make it difficult to find the right choice.
This article will review the differences between CCX and CDX construction-grade plywood, helping you decide which of the two – if either – is best for you.
CCX vs. CDX Plywood: What Are the Differences?
Let’s jump right in.
1. Grades
CCX and CDX are acronyms describing different grades of exterior plywood, also known as plywood sheathing. Plywood is graded using a system that rates the quality of the front and back surfaces.
2. Grades range from A to D:
- A: The surface is sanded with virtually no defects and is free from knots
- B: The surface is sanded with some defects repaired with wood filler
- C: The surface is unsanded with repaired or patched defects and knots up to 1-1/2 inches
- D: The surface is unsanded with large sections of repaired defects and patches with knots up to 2-1/2 inches
CDX has one C-grade face and one D-grade face, giving it a clear front and back. CCX has two C-grade faces, leaving it the same quality on both sides.
The X stands for “exterior,” which is the rating of the glue used to bond the veneer layers. This gives the wood some moisture resistance for outdoor use, but it still must be covered for long-lasting protection.
3. Material
Both CCX and CDX are softwood plywood varieties (as indicated by their grading–softwood uses letters, while hardwood uses numbers). Pine, spruce, and fir are normally used for plywood production. These are the varieties you will find in a typical hardware store.
Other conifers, like cedar and redwood, are also found among specialty lumber wholesalers.
4. Thickness and Sheet Size
Plywood nominal thickness ranges from 1/4 to 1-1/4 inches, offered for both CCX and CDX.
A note on nominal thickness: nominal thickness is the thickness the product is listed at, but plywood actual thickness is always approximately 1/32-inch thinner. This actual thickness must be accounted for in your measurements to ensure a tight fit.
The most common sheet sizes come in 4 x 8, 4 x 9, or 4 x 4 feet. Other specialty options, 2 x 2 and 2 x 8 feet, are becoming more popular.
5. Strength
The strength of plywood is determined by the number of layers, or plies, and the thickness of the board. With a minimum of 3-ply, varieties can be found up to 7 layers thick.
Due to the better quality of the wood overall, CCX does have a strength advantage over CDX when all other factors are the same.
6. Price
In 2022, you can expect a 4-ply 1/2-inch thick 4 x 8 foot piece of CDX to cost between $32 and $35. A similar piece of CCX is between $48 and $52. Some treatment options, such as pressure-treating for ground contact, will increase this cost, as will increased thickness.
Finding untreated CCX in your local hardware store can be a difficult task, and may require a special order.
Though sold at a higher price point, CCX can cost less overall: due to the front and reverse sides being the same quality, less waste is produced, saving you money.
When to Use CCX Plywood?
Standard CCX (not pressure treated) can be used in general construction applications, such as subfloor and roofing, or in outdoor applications, like shed and playhouse walls and fencing. Certain pressure-treated CCX varieties can also be used for direct, prolonged contact with the ground or even freshwater.
Another reason to choose CCX relates to the design and your personal assembly style. If both the front and reverse sides will be visible in the finished product, CCX is the better choice. If you are like me, and you pay no heed to which side you are cutting from, CCX will also save you time, money, and frustration.
When to Use CDX Plywood?
CDX is the typical construction-grade go-to plywood. It is used for subflooring and roofing, outdoor structures (e.g. sheds), and indoor utility shelving. It is a great option for those that are looking for a cost-effective solution when aesthetics aren’t a priority, and the product will be covered.
When using plywood in exterior applications, this should serve as a reminder that only the resin glue in both CCX and CDX is exterior-rated. It is mildly water-resistant, but won’t withstand the elements for long without protection, such as sealant, paint, or siding.
Neither product should be used for prolonged contact with high moisture (unless treated for that purpose), as the wood will warp and layers may separate.
Alternatives to CCX and CDX Plywood
If neither of the two plywood types seem like the right option for you, you should also consider other types of engineered wood including:
1. OSB
Oriented strand board, or OSB, is a common substitution for plywood. OSB is made by combining resin, glue, and wood chips, placing the mixture under pressure to form a sheet, and baking it at a high temperature. At approximately half the cost of plywood, OSB is a smart choice for projects that won’t be seen.
Also, because OSB doesn’t expand and warp in high-moisture environments, it’s often the preferred material of professionals for roofing underlayment.
2. MDF
Another low-cost alternative to plywood is MDF. Short for medium-density fibreboard, it is made by breaking down hardwood and softwood into a pulp, combining the pulp with resin, and setting it into a sheet under high pressure and temperature.
The surface of MDF is smooth and consistent, making it perfect for projects where a smooth finish is required for painting (MDF can’t be stained). It is best suited to indoor projects that won’t be under constant stress or pressure, and won’t be exposed to any moisture.
Summary
Both CCX and CDX are excellent choices for structural construction projects. This article addressed the differences and similarities between the two, along with which types of applications would be best for each product.
Do you know which option you’ll be planning to use in the future? Hopefully, we helped make that decision easier so you can get out and start building sooner.