Defective material? Foil-faced polyiso left exposed longterm - impact to R-Value? OSB which stands for oriented strand board, is composed of wood chips bonded together with resin and glue. I have a good test case for this: a doghouse roof. Some small knots are allowed in the face/back. Eventually either the glue bond fails or the wood shears along the glue, and the plys separate. Whether or not they’ll do anything about it is another story entirely. The ‘CDX’ is actually a combination of ratings that provide information as to the quality and construction of the plywood. By necessity we frame in the rain here in the PNW. Granted, CDX plywood is never used as the final exterior layer, because of its lack of durability. During the CDX plywood adhesive process, manufacturers carefully position the wood grain elements of the plywood so that they are aligned in a way that reduces shrinkage. You can simply do it by yourself with the help of the following methods. While this may sound similar to CDX plywood, it is a very different composition process, and OSB board is generally much less durable than CDX plywood. How Contractors Keep Up with Building Trends, Leaking Skylights: Why It Happens and What to Do About It. Exterior grade plywood can be used indoor , too . Inside of the home, CDX plywood is often used as an additional flooring layer that rests just below the carpet pad or as a backer board for tiling. Plywood sheets that rank A or B tend to be the most expensive pieces, whereas C-level and D-level plywood pieces are more affordable and cheaper in quality, making it a more economical option. The face/back of CDX plywood is flat. These features are assessed and then assigned a rating – either A, B, C, or D. Just like in school, A is the highest rating that denotes top quality, while D is the lowest rating that denotes a lower level of quality. In addition to these structural uses, CDX plywood is also commonly used for minor utility purposes, such as rudimentary shelving in basements, storage cabinets, or sheds. Depending on the quality of glue used, the plywood will be more or less susceptible to damage due to exposure. But exterior plywood is more expensive than interior grade plywood . To ensure a long life of plywood outside, it is necessary to weatherize it. Cons of CDX Plywood. Plywood in general – and especially CDX plywood – is known for being susceptible to damage from everyday elements. If you use interior plywood outdoors, it won't be long before the corners of the sheets separate, and eventually the plywood will become spongy and disintegrate. Whether you’re building a small bookcase or backing exterior siding, the type of home construction project will make a big difference as to whether or not CDX plywood is fit for the job at hand. Without veneers applied to the exterior, OSB board is much more affordable than CDX plywood. Usually, CDX plywood is sanded but not polished. The Best Ways to Paint and Seal Plywood. what does the color pewter look like? When you think about it, this single piece of CDX plywood actually has a lot of elements to consider! But the truth is that, even though both OSB and CDX plywood are commonly used in a single home construction site, there is a big difference between these two plywood types! The exposure rating is supposed to let the material be exposed for a reasonable period of construction, which I’d think should be at least a few weeks to a few months. Because the core veneers for CDX plywood are not as good as exterior plywood. As Bill said, If you are experiencing widespread failure there is something wrong with the plywood. Nonetheless, CDX plywood ranks as a convenient and affordable sheet of wood composed of several layers. Your source for the latest products and trends within the architecture, construction, interior design, and building materials industry. Your email address will not be published. However, because of its low-quality exterior, CDX plywood is not often used for pieces of furniture that require a more finished appearance inside the home. Moreover, this plywood type absorbs water, slightly expanding all the while. It's rated for exterior exposure during construction. Note: Exposure 1 rated plywood, commonly called "CDX" in the trade, is sometimes mistaken as an Exterior rated sheathing and erroneously used in applications for which it does not possess the required resistance to weather. CDX plywood sizes are typically available in sizes 3, 5, 7, and 9, and there are a variety of thicknesses available, ranging from 1/4 inch to 1 1/4 inch thickness. In addition, the resin and glue bonding approach actually makes OSB board better suited for enduring moisture, unlike CDX plywood which can become warped when moisture builds up between the bonded layers. What does it mean for our homes and how can we protect ourselves? That is why manufacturers have come up with a solution that reinforces the integrity of CDX plywood to make it better fit for holding up against rain, snow, humidity, and mold. How long can CDX plywood be exposed in winter? However, they are not suitable for long-term exposure post-construction. CDX plywood is moisture resistant but can not be exposed to water or weather for long time . Picking the right type of wood for home building projects is absolutely essential, as the type of wood can impact performance, durability, and long-term maintenance to be expected. It only took a few months to start having problems on that side. For example, many first-time homeowners confuse CDX plywood with OSB plywood. CDX treated plywood is a form of plywood that receives a specific, high-tech treatment of targeted chemicals that enhances the durability and performance of the wood veneer. In addition, 3/8, 1/2, 5/8, and 3/4 thicknesses are usually available at most stores, too. To give the project a better appearance, a coat of paint may be necessary, if the end product looks poor due to the low grade of the plywood. This CDX plywood is a kind of economical plywood. Plywood holds up well to sharp blows, fork tine impact and other in-service abuses, which in turn means lower replacement costs. Sometimes, a lower quality wood is used for interior layers, reserving the better layers for the outside. "CDX" should only be used for applications as outlined under Exposure 1 above. Antonius J. And as most homeowners know, continually repainting, staining, or replacing segments of full sheets of CDX plywood panels can be a pain. Above: Plywood makes for neutral and streamlined kitchen cabinets; see Kitchen of the Week: Eclectic English Kitchen, Color Included for more. Residential PV Installations in Florida Remain Strong. When it comes to CDX plywood, the ‘X’ signifies exposure, which means that while CDX plywood is slightly water-resistant, it is not waterproof, and therefore the CDX plywood can only withstand a limited amount of moisture over a short period of time before showing signs of degradation. Unless you had some kind of major deluge for five days with a long period of mugginess after so the material could never dry out, I think you have a case with the manufacturer. Many smaller DIY projects can use CDX plywood as long as appearance isn't a primary concern.