CDX Plywood: What You Need to Know
Despite the fact that wood has been a major raw material for mankind for many centuries – which has allowed us to make magnificent architecture and buildings – the omnipresence of its contemporary counterpart, plywood, is fairly new. It was first patented during the mid-1800s, and since then, it has slowly started gaining popularity for commercial and residential usage. From CDX plywood to ACX plywood, there are various types of utility grade types of this exterior covering in the market, and it all depends upon the application and purpose of the roofer. The smoother the front and back sides of the plywood, the more expensive it tends to be at a lumberyard. From decking to floorings of residential properties, there are various usages of plywood.
How is Plywood Made?
It is made of a combination of three or more sheets of wood that are joined together with the help of a special adhesive – which keeps them intact for many years to come. Unlike solid wood, which is highly susceptible to getting expanded or contracted due to external factors, plywood has the quality of maintaining the same dimensions throughout its lifespan. In order to reduce the level of shrinkage, the wood grain of each layer is placed in a way that it makes a right angle with its adjacent layer. When the each individual ply forms a perpendicular with its internal or external sheet, it prevents the wood from growing in any direction – which can potentially affect its original dimensions.
In the beginning of the manufacturing process, logs of different types are gathered from different outdoor sources, and then they are separated in terms of species and quality. The layered construction technique gives plywood a unique leverage when it comes to having a highly aesthetic wood flooring or sheathing at an affordable price. Face veneers – which are the outer coverings of either sides of the plywood – are carefully selected, so that the appearance of the product can be maintained. On the other hand, lower quality of wood is used for inner layers, which reduces the overall cost of raw material required for a single unit.
What is CDX Plywood?
CDX plywood is a highly popular choice among homeowners for roof sheathing as it has the quality of withstanding moisture and water for a substantial period of time. Unlike the common perception, the “X” doesn’t denote to the exterior covering of the sheet, but it is actually referred to the type of glue used as an adhesive in the final product. Despite the fact that it is considered the cheapest form of plywood in the market, it is widely purchased by industrial clients in bulk quantity for the application in the related sector.
This multi-layered veneer plywood is highly sought after in the construction industry because of its sturdiness and strong material. The plies are combined in odd numbers so that a proper balance of sheets can be established, which in turn would prevent the warping of the wooden structures. They usually come in piles of 3, 5, 7, and 9. For outdoor usage, the panels are pressure-treated so that they can withstand maximum amount of force and pressure without breaking apart.
The Letter X
The letter X basically refers to the type of adhesive used during the manufacturing process to stick each individual ply with one another, so that they don’t get unattached easily after being subjected to load or pressure. The “X” in CDX stands for exposure, which means it has water-resistant quality and it can be used in places where the exposure with water is highly probable to occur.
It is designed to be installed in living spaces of the house which have higher chances of being drenched in water, such as laundry area, bathroom, and kitchen. You can also apply it as sheathing in areas where the level of dampness is high, such as basement where the ratio of humidity in the air is quite high. Because of the fact that a particular panel of CDX covers a large surface area, it is advised to use it for large-scale projects rather than using it for minor project, such as bookshelf. If you have carpeted flooring in some rooms of your residential property, then you can use it as sub floor – which would in turn add stability to the structure.
The Letters “C” And “D”
The grading system of plywood is fairly easy for an inexperienced individual to interpret, so that easily purchase panels according to their requirements from a local lumberyard. The grading ranges from A to D, which indicates the quality and lifespan of the panel. If the presence of knot holes and random voids is higher in a particular unit, then it would be allotted the lowest grade based on its apparent condition. In order to minimize the chances of discovering any potential defects in panels, the wood mills spend time and effort to fill up all those gaps and voids.
The highest qualities of plywood panels have ratings of A and B, which means that most of the voids have been patched by special material so that the wood has minimum chances of expanding in any particular direction after absorbing water or moisture. The plywood sheets with ratings C and D are considered highly economical, and they are used for low budget projects. You would easily be able notice random patches that have a shape like football, and it is not an aesthetically appealing type of panel. But the appearance doesn’t matter for clients that want to purchase C-grade plywood, as they are more after the functionality and price of the product. You would be able to see discoloration and sanding defects, which would mainly affect the overall outlook of the plywood rather than decreasing its strength. Because of its limitation to withstanding constant moisture in the surrounding area, you might have to use another sturdy material to keep it fully covered. It can also be sanded easily, so you might have to consider replacing it after a few months.