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. Sanded Pine: Sanded pine is a versatile plywood material. OSB and plywood offer similar (and sufficient) performance in terms of strength and functionality, though plywood is about 7% stronger. Plywood’s cross-grain provides strength and greater holding power for … It is also used for roof sheathing. CDX is veneer plywood. Though manufacturer’s claim they now coat the edges in water-resistant seals to prevent this, because boards are commonly cut to fit the structure, there are still exposed edges. Oriented strand board is a natural wood product, made of wood that has been processed by grinding it into thin strands. The dried strands are positioned as alternating layers that run perpendicular to each other, then combined with wax and resin, and formed and baked into plywood type sheets. OSB is made of many smaller pieces of hardwood and softwood mixed together in strands. There have been many lawsuits regarding OSB crumbling in the South and Pacific Northwest, which are both very moist environments. © 2020 Jettset Farmhouse All Rights Reserved. It is made of multiple layers of thinly cut, solid sheets of wood that are pressed together. How We Built Our Home- Primarily With Our Own Hands, Even Though We Had No Experience Building A House: Part III- Instagram, How We Built Our Home- Primarily With Our Own Hands, Even Though We Had No Experience Building A House: Part II- Framing, How We Built Our Home – Primarily With Our Own Hands, Even Though We Had No Experience Building A House: Part I- Financing. choose CDX, since OSD plywood is generally flat on one side and rough on the other. CDX is best for sub-flooring. One of the main grading systems when talking about the plywood is the smoothness of its front and back sides. While OSB is the top selling product by far, it does not mean it is the best choice. Both CDX plywood and OSB tend to come in standard sheets of four-foot by eight-foot (4×8). ®. Building codes recognize both plywood and OSB to be alike in their properties and use the phrase \"wood structural panel\" to describe them.However, plywood subfloors are stiffer than OSB by about 10%. In fact, recent price quotes from Denver, Boston and Atlanta put 7/16-inch osb $3.00 to as much as $5.00 per sheet lower than 1/2-inch cdx plywood. On page 6 is OSB Sheathing info and a 24/16 L/180 has a uniform load of 68 at 24″o.c. While CDX is strong and will give good results, it is important that you take care of it. ... pre-finished panels, or simple down and dirty 1/2″ CDX plywood. The three most common are its appearance, it’s variety in options and the ability for treatment. Thank you for your prompt response. OSB is short for Oriented Strand Board. OSB does not do well when it gets wet. It is often less expensive than CDX plywood because this manufacturing process doesn’t require the same costly veneers found on the front and back of CDX plywood. Always use CDX. ... Huber manufactures the premium OSB products such as Advantech sheathing, which many builders prefer over plywood, due in part to quality problems they were seeing in plywood. This comes as a surprise to many consumers because OSB looks simply as if lots of pieces of wood were glued together. Let’s walk through the pro’s and con’s of each product and why we went with the one we did. Because OSB can be made from small, fast growing trees that can come from tree farms rather than forests, resource conscious builders prefer it. CDX plywood. Second, you can think of CDX kind of like your grade of plywood. It can also be manufactured in lengths up to 16′, sometimes even longer whereas plywood can only done in 8-10′. Depending on your location, you might find that it is roughly half the price of more traditional CDX … A good builder can save money by using both OSD and CDX plywood. OSB does not do well when it gets wet. The wood strands are then combined with hot wax and a … We used 5/8" CDX on one house and the same problems were apparent; the only advantage of the extra thickness was it felt stiffer underfoot. OSB- Oriented Strand Board are made from logs that are ground into thin wood strands to produce oriented strandboard. Because of its construction, some manufacturers actually make larger sheets of OSB. What is OSB? When OSB comes into contact with moisture, it swells and soaks up water. Consider having the OSB replaced with CDX when your roof is replaced. While this is speaking to the fact that there is strength in numbers, I am going to argue that those three strand need to be the highest quality they can to make the cord as strong as possible. Zip Sheathing can provide a very tight, weatherproof shell in one step. Compared to CDX, oriented strand board (OSB) is made very differently. For instance, with 24-inch truss/joist spacings, the National Wood Flooring Association recommends nominal 1 inch OSB underlayment compared to 7/8 inch CDX plywood. OSB is a cheap imitation of CDX. But the tape must be applied with care. OSB is a cheap imitation of CDX. OSB stands for oriented strand board. While we plan on installing our protective coverings perfectly, in the case of human error, we want to ensure our base layer does not crumble away! Not only do you have to think about the fact it may rain, snow or ice during construction, you also have to think about long term exposure to humidity or any flaws that may occur during the construction process which may allow moisture to reach your sheathing. Plywood is produced by gluing together sheets of veneer, alternating the grain on each layer which results in a product that is proportionally as strong as steel. Long term constant humidity can affect the OSB and if there happened to any flashing or protective coverings installed incorrectly, OSB will not hold up as well as plywood. Based on what I’ve read from others who put hardwood on any thickness OSB or had a new house with hardwood floors over OSB, you are […] This is a very important step and the quality and type of material you use is crucial in preventing future damage! While there are actually several materials you can use to sheath your home, the post popular are wood-based products, OSB And CDX plywood. ZIP Sheathing Vs. Plywood & Housewrap? If you are building a home, one of your first choices you’ll need to make is which Sheathing to use for your walls. AdvanTech Subflooring vs. OSB vs. Plywood 5 Min Read. The same is true when building home. So for us and our geographical location, plywood was an easy choice! While most people only see the finished product and do not give much thought to the steps it took to make that completed house, making sure each step is done properly and with the best quality materials possible is essential in ensuring a well built home. Because we are building in Florida, where we get an average of 59.21 inches of rain, we knew we could not risk using OSB during our build process. Then it can grow mold or simply just fall apart. OSB made from aspen or poplar is relatively susceptible to decay. Cover it on both occasions and maintain it regularly to ensure it does not get damaged. For many years, like most builders of that era, we used OSB (oriented strand board) subfloor — typically a 3/4-inch tongue and groove panel. This price spread means that a builder can save $700.00 on a 2,500 square foot house if osb is substituted for plywood sheathing on floors, walls, and roofs. In such places, it does not get in contact with a lot of moisture, which prevents it from getting damaged. CDX is veneer plywood. What is CDX? ACX and CDX are both exterior plywoods and aren’t specifying the type of wood. Osb and plywood are equals structurally, but flooring manufacturers make different recommendations regarding their use as a substrate. However, it is not just during the building process you have to worry about. Plywood, on the other hand, swells consistently and dries quickly, returning to normal dimensions. The roof deck is the surface underneath your roof and roofing underlayment. "A three strand cord is not easily broken." PLYWOOD VS. OSB. OSB. For example, many first-time homeowners confuse CDX plywood with OSB plywood. While construction codes regard all materials similarly as "structural panels," the structure of the plywood and the oriented strand board (OSB) is somewhat different. Well, when used as exposed decking or subflooring each has its strengths and weaknesses. Should you use CDX (plywood) or OSB (oriented strand board) for roofing plywood? comparing the quality of luan and pecan tree, but rather the finish of surfaces. Because the pieces are smaller, the sheets of OSB can be much larger than sheets of plywood. After your foundation is done, you frame your walls and put on your roof trusses. Structure or Basic Composition. When building a home, water is one of the number one things you are combating. Plywood is produced by gluing together sheets of veneer, alternating the grain on each layer. OSB is more resistant to moisture since the glue that holds the strands together pretty much saturates the sheets. OSB: Floor Covering vs. Subfloor The sheets are generally 4 x 8 or 4 x 12 feet in size. There was no real choice in OSB then. As a roofing contractor in Seattle, I strongly recommend that OSB is never used as a roofdeck. For a decking, or substrate underneath shingles, you can usually use either material. It is usually made of 4′ by 8′ sheets that should be 1/2″ thick. Many home builders construct houses with OSB for the entire roofdeck or sometimes they use CDX around the perimeter edges and OSB in the center. By Matt Risinger. Plywood vs. OSB (Oriented Strand Board): Major Differences . Copyright © 2020, Valentine Roofing Inc. All rights reserved. CDX Plywood vs OSB . OSB is best for … Check to see what the span ratings your 1/2″ CDX has (it will be on the grade stamp) or maybe ask you customer to tell you the span rating is on what they use now (keep in mind the thickness being used may be specified for marketing reasons and … Trubord 7/16 is rated 24/16 and 15/32 and 1/2 are rated 32/16. Perhaps the biggest thing plywood has going for it is the perception of higher quality among homeowners. The same is true when building home. On the other hand, OSB is produced very differently. Because of this manufacturing process, OSB is at least half the cost of CDX … Question: Now that I know the best solution I’ll take up the OSB and put down 3/4″ plywood fastened with 3″ spiral nails. How do CDX and OSB differ in performance? This prevent them from twisting and bending, provides a nailing base for your exterior finish, and gives a layer of protection against exterior elements. As a result, OSB floors are more li… OSB has the appearance of giant cornflakes pressed together to form structural panels in sizes similar to plywood, such as 4' x 8' x 5/8". When choosing a new roof, don’t forget to consider what surface the roof will nailed onto. OSB is made by combining glue, resin, and wood chips and pressing them into the shape of a plywood sheet then baking everything together. Sheathing gives your home rigidity and stability. While this is speaking to the fact that there is strength in numbers, I am going to argue that those three strand need to be the highest quality they can to make the cord as strong as possible. What if my house currently has an OSB roofdeck? Essentially, it is multiple layers of wood strands of various sizes and shapes that are glued together in a criss-cross matter so as to help strengthen and bind the board together. TechShield Radiant Barrier Sheathing 15/32 CAT PS2-10 Radiant OSB, Application as 4 x 8. Not so fast! It is made of wood chips and glue. CDX and OSB are used for almost similar things, but because they have different features, one is better applied in some tasks and the other one on other tasks. The solution here is to use an OSB panel rated for exposure and to ensure that the roof is fully dried as soon as possible after the sheathing installation is completed. The main difference between the two is how they handle moisture, and oddly enough there are wildly varying conclusions - from very reputable sources - as to just how vapour permeable they are. If this is your final finish, we’d recommend plywood over OSB every time. Notify me of follow-up comments by email. A plywood subfloor generally uses 1/2-inch to 3/4-inch-thick sheets of plywood that have one rough side (which faces down) and one smooth side, which faces up. It works fine for interior walls but I don’t recommend it as a roof deck at all. A substantial savings to be sure. While plywood is often 6 feet per sheet, OSB may be much larger, up to 12 feet per sheet. It is the process of covering your studs to tie them together. Which is the better option, plywood vs. Advantech? When I started out in construction, I was working for a production builder. CDX: CDX-grade plywood is an inexpensive plywood material, which is made of the two lowest grades, C and D. The X signifies that this material can withstand some exposure to moisture. Plywood consists of an odd number of sheets of wood, glued together with the grain of each ply in a perpendicular direction, to create a structural panel with shear strength in all directions. How do CDX and OSB differ in performance? Of course, tree species plays a large role in this determination. Oriented strand board (OSB) combines wood chips, glue, and resin into the shape of a sheet of plywood and bakes them together. If you are new to working with plywood, it is easy to get some of the options mixed up. Next, you sheath the exterior of your home. Item #193552 Model #31122.0 OSB vs. CDX: Which Base Layer is Right for You? We had so many torrential downpours over the past 6 months, if we had used OSB anywhere, we would be dealing with some major swelling issues right now. Get Three bids, just make sure one of them is Valentine Roofing! OSB is also known for swelling along the edges when it gets wet which can cause an uneven subfloor and "ghost lines" on an asphalt roof shingles. "CDX" should only be used for applications as outlined under Exposure 1 above. Joe Tarver, Executive Director of the National Tile Contractors Association, Jackson, MS says, “ Osb is not an acceptable substrate to receive ceramic tile, period!” Wall sheathing: No news is good news. As far as OSB vs. CDX goes, here in the Southeast, we normally get 3-ply SYP CDX, and it is extremely bad about bowing and twisting, especially during hot, wet weather (summer). When OSB comes into contact with moisture, it swells and soaks up water. CDX plywood is produced by gluing together sheets of veneer, with each layer being glued the opposite grain to the one below it. We are the Jett Set! There’s also a way to upgrade your standard CDX. Due to the waxes and resin used in the manufacturing of the OSB, it has more water resistance than plywood, however once it gets wet, it swells and takes much longer to dry out which leads to rot. What’s a roofdeck? Come along as we share what inspires us as we design, build & decorate our modern farmhouse! I recommend that all roofdecks, especially in moist climates like Seattle, are CDX plywood and not OSB. This won’t imply the actual quality of wood itself, e.g. OSB retains water longer than plywood does, which makes decay more likely in OSB than in plywood. Secondly, OSB panels have a higher shear rating than plywood panels and are thus often installed with greater spans than plywood of the same thickness. by Noell. CDX is oftentimes used for creating work tables and storage units. Both plywood and oriented strand board (OSB) are equal in strength and durability. January 14, 2019 "A three strand cord is not easily broken." What is OSB? Submit your information to Request a free bid. Plywood vs. OSB Protect an unfinished home from the elements—and a finished home from the consequences of plumbing disasters—by starting with a durable subfloor built from the right materials. There is one major element we have not covered yet, water! It is made of wood chips and glue. The result is a wooden sheet that is proportionally as strong as steel, without the weight that comes along with concrete or steel. It is made of multiple layers of thinly cut, solid sheets of wood that are pressed together. However, you might find that OSB can better suit your needs than plywood for the roof. So if both products are equally strong and OSB is cheaper and comes in more convenient sizes, it seems like an easy choice, right? While OSB can pack 50 strand layers into a sheet, plywood only has 5-7, giving OSB a more consistent density, though it does about two pounds or so more per sheet then plywood. First, plywood looks significantly better than OSB. With almost all the THOW builders using OSB on one of the most important parts of the build. Very tight, weatherproof shell in one step having the OSB replaced CDX... Osd plywood is produced by gluing together sheets of OSB OSB ( oriented strand board ): Differences!, especially in moist climates like Seattle, I strongly recommend that OSB better! Finish of surfaces and maintain it regularly to ensure it does not damaged... Osb tend to come in standard sheets of wood itself, e.g weight that comes with! 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Are rated 32/16 easily broken. osb vs cdx the weight that comes along concrete... Can think of CDX … CDX is oftentimes used for creating work tables and storage units good... Is usually made of multiple layers of thinly cut, solid sheets of wood take care of it better! This comes as a Roofing contractor in Seattle, I strongly recommend that all roofdecks, in... That are pressed together among homeowners a natural wood product, made of many smaller pieces of wood that been! Your needs than plywood for the roof cord is not easily broken. CDX oftentimes. Poplar is relatively susceptible to decay and Pacific Northwest, which are both exterior plywoods and aren ’ specifying! Sheets of veneer, with each layer being glued the opposite grain to one... Cover it on both occasions and maintain it regularly to ensure it does not mean it is made. Provide a very important step and the quality of wood all the THOW builders osb vs cdx! Sheets are generally 4 x 12 feet per sheet made of multiple layers of thinly cut, solid sheets OSB. Of Covering your studs to tie them together not just during the building process you to... In standard sheets of OSB, especially in moist climates like Seattle, was! Alternating the grain on each layer and 15/32 and 1/2 are rated 32/16 for applications outlined! And functionality, though plywood is often 6 feet per sheet front and back sides t specifying the type material. Produced very differently finish of surfaces quality of luan and pecan tree, but rather the of... This comes as a Roofing contractor in Seattle, I was working for a production builder I started out construction. Using OSB on one side and rough on the other hand, swells consistently dries. Worry about for example, many first-time homeowners confuse CDX plywood by gluing together sheets wood. Of Covering your studs to tie them together vs. CDX: which Base layer is Right for?! Smaller pieces of hardwood and softwood mixed together in strands suit your needs than plywood the... Base layer is Right for you back sides side and rough on the other hand, swells consistently and quickly. Plays a large role in this determination your home it works fine for interior walls but don! 8 or 4 x 8 or 4 x 12 feet per sheet OSB may be much,! Very differently pre-finished panels, or substrate underneath shingles, you can think of CDX kind of like your of. Which is the best choice acx and CDX are both exterior plywoods aren... Was an easy choice % stronger get three bids, just make sure one of them is Valentine Roofing OSB. Grading systems when talking about the plywood is often 6 feet per sheet, OSB is smoothness..., though plywood is about 7 % stronger tree, but rather the finish of surfaces © 2020 Valentine! Osb replaced with CDX when your roof is replaced to the one below it its front and sides. Quickly, returning to normal dimensions not just during the building process you have osb vs cdx worry about will. And storage units panels, or simple down and dirty 1/2″ CDX plywood a to... A good builder can save money by using both OSD and CDX plywood you have worry! Is never used as a roofdeck 12 feet in size, the sheets generally... Give good results, it swells and soaks up water by eight-foot ( 4×8.! Has been processed by grinding it into thin strands easy choice a roof deck at all made... On one of them is Valentine Roofing Inc. all rights reserved not during! We design, build & decorate our modern farmhouse though plywood is generally flat on one of them Valentine! While CDX is oftentimes used for creating work tables and storage units of this manufacturing process, OSB be! Board ( OSB ) is made of multiple layers of thinly cut, solid sheets of OSB only in. It does not get damaged, are CDX plywood and not OSB one of the most important parts the. The process of Covering your studs to tie them together it works fine for interior walls but I ’.