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  • Writer's pictureNicholas Tapia

CDX Plywood vs OSB: Choose the Right Decking for Your Roof

When it comes to roof decks, you have two main options: CDX plywood and OSB (oriented strand board). Both materials are strong and durable, but there are a few key differences that you should consider before making your decision. In this blog post, we'll discuss the benefits of each option so that you can make an informed decision about which material is right for your roof decking project in rainy Portland, Oregon.


CDX Plywood

cdx plywood

CDX plywood is one of the most popular choices for roof decking because of its strength and durability. It is made up of several layers of wood veneer that are glued together in alternating directions, creating a strong bond that can handle large amounts of weight and pressure. Additionally, CDX plywood is

relatively lightweight compared to other types of plywood, making it easier to work with during installation. Finally, CDX plywood is treated with preservatives to protect it from moisture, rot, and decay—making it an ideal choice for outdoor projects like roof decking.


OSB Plywood
A stack of OSB

OSB (oriented strand board) is another great option for roof decking because it is strong and cost-effective. It consists of strands or flakes of wood that are bonded together using adhesives and heat-pressed into boards. Unlike CDX plywood, OSB has no grain direction—meaning it can withstand large amounts of weight regardless of how the boards are oriented during installation. Additionally, OSB can be treated with preservatives to help protect against moisture damage—making it a good choice for outdoor applications like roof decks. The only downside to using OSB over CDX plywood is that it tends to be heavier than traditional lumber or plywood sheets, which means it may require more labor during installation.



Plywood on a roof
Plywood on a roof

When it comes to building materials, plywood and OSB are two of the top choices. Plywood generally can handle moisture more efficiently than its counterpart; when exposed to wet conditions, swelling is uniform throughout the sheet before returning back down once it dries out again. This is a great feature in rainy climates like the Pacific North West. Unfortunately for OSB boards, however, exposure can cause irreparable damage - so always ensure that there isn't any contact between these panels and water! To further protect against this threat in construction projects where cutting may occur during installation, newer innovations have been made with reinforced edge seals that resist moisture penetration. And if a roofing issue should happen such as a leak or some other unforeseen circumstance arises? Opting for plywood would be worth considering -- saving time on repairs while also supplying long-term structural stability!



When choosing between CDX plywood and OSB for your roof decking project, there are several factors to consider including cost-effectiveness, strength & durability, weight & ease-of-installation and overall protection against weather elements such as rain & sun exposure. Ultimately both materials offer their own set of benefits depending on the needs and preferences of each individual project – so when in doubt always consult a professional contractor who can advise on the best material choice given your specific situation! Because of the moisture factor, we will always recommend CDX plywood. With this information in hand, you’ll be able to make an informed decision about which material will work best for your roof decking needs!


Bottom Line

When it comes to roof decks in rainy areas like Portland and the Pacific Northwest, CDX plywood is your go-to material for superior wet performance - something that's absolutely essential. Trust us when we say no other option will give you as much peace of mind!

Contact us for a quote on your roof.


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