First, wood shrinks as it dries and moisture leaves the wood. These will usually be a distinct color (green or yellow) caused by the resin they were pressure treated in, causing them to stand out from standard exterior grade plywood. This type of plywood won’t sag when used on a 12 inches joist structure. It is usually made from fir or pine, just like CDX. Even roof felt would be enough to (likely) protect it until the weather warms up. ACX also on hand for telecommunications panels / phone-board. There are a few reasons why the actual thickness of plywood varies. (c) 5-ply applies to plywood with 5 or more layers; for 5-ply/3-layer plywood, use values for 4-ply plywood. If you’re in the middle of a project and a summer thunderstorm drenches your roof sheathing or the walls of the garage you’re erecting, relax…your project will be fine. The difference between interior and exterior plywood is in the resin glue which is used to hold the various layers of veneer together. Roof sheathing may be supported by H-clips, in addition to being nailed to the rafters. This means that a sheet of plywood that started at 3/4” may shrink slightly after manufacturing. Fire Retardant Treated Plywood: 1/2", 5/8", 3/4". (b) Shear through the thickness design capacities are limited to sections two feet or less in width; wider sections may require further reductions. Interior grade plywood, made using resins that can’t withstand water and weather as well, are not considered to be structural grade plywood. Get hassle-free estimates from local trim carpentry professionals and find out how much your project will cost. Therefore, it is much easier to use CDX. Any such shelving made of OSB requires special construction techniques, so that there is a secure means of fastening and supporting the panels. Formation. But, you can also run into problems if you go too thick. The only exception is plywood which is stated as “having no voids,” such as marine grade plywood. CDX Plywood Thickness Availability. This means that if they expand at all, due to water absorption, they will buckle in some manner. The most common thickness of plywood is 1/2-inch, but plywood thickness can range from 1/8-inch to 3/4-inches. Then, once it has dried, sand it smooth, providing you with the surface you need for painting. 1/2″ plywood is used for building furniture parts, boxes and … If the thickness of plywood increase 3mm, the No. When placed across equally spaced beams, joists or rafters, CDX is almost 10% stronger than OSB, the other alternative which is often utilized as a subfloor due to its economy. Georgia Pacific 1/2" x 4' x 8' 4-Ply CDX Plywood. This plywood is moisture resistant but not meant for long term weather exposure. It is rot resistant with knots replaced with football shaped plugs to give it a smooth moisture-resistant surface. Plywood is generally available in 4’x8′ sheet and is cut into a square board. You might want to give any exposed CDX plywood some protection, especially exposed roof sheathing. This support keeps the shelf from sagging. This type of plywood is also referred to as “structural plywood;” a designation which means that it is intended for structural applications. than CDX plywood. The threshold for this is about four months. An odd number of glue layers would cause the glue to pull towards one direction, causing warping of the panel. 5/8 inch. Actual Width. Otherwise, it will absorb water, with all the ensuing problems. : ¼ inch panels are actually 7/32” or ¾” panels are actually 23/32” etc. Therefore, in applications where the stability of the plywood is important, it is better to use fir than pine. Marine grade plywood also has better face veneers than CDX, which are sanded smooth. Sheets are available in hardwood or softwood veneers, and in varying grades including sanded and unsanded. Therefore, the wood itself is not as dense as it is with hardwoods. It still requires waterproofing, especially on the edges, to protect the end grain. Better yet, install a layer of lauan plywood over the CDX plywood, as an underlayment, providing a smooth surface for the vinyl flooring to be mounted to. The weight of a panel will vary by thickness and the type. Moisture resistance • Plywood absorbs water faster and dries out faster than OSB. CDX plywood sheets are also available in a fire retardant variant, though those sheets come with a much heftier price tag. A 3 / 4 ” sheet is actually 23 / 32 ” thick. The nominal thicknesses of plywood range from 1/8 inch, or 3.2 mm, to 1 1/4 inches, which is equivalent to 31.75 mm. When it comes to choosing a subfloor for a ceramic tile floor it is always best to choose CDX plywood over OSB— it’s stronger and doesn’t have the problems with moisture that OSB does. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to,,, The Ultimate Guide to Sealing Laminate Floors, Install a Combination Boiler/Water Heater, Exterior Walls Construction: The Start-to-Finish Guide, The Uses of and Challenges in Cutting Formica, The Ultimate Guide to DIY Birdhouse Design, Aquarium Cabinetry: A DIY Guide to Custom Aquarium Stands, The Ultimate Guide to Building a Bat House, The Ultimate Guide to Building a Portable Generator Enclosure, How to Remove and Replace Your Load Bearing Wall, Drying Wood in the Oven: The Ultimate How-To Guide, How to Cut a Groove or Channel on Wood Without a Router. Today, more and more lumberyards are stocking their CDX plywood with more accurate descriptions, referring to: CDX plywood is used for a number of applications, including: Construction sheathing of walls and roofs. The veneers used in the core layers will also have permitted voids and splits. Even ¾” thick plywood cannot cover a broad span, supporting weight, without sagging. As the most common plywood product available on the market, CDX plywood is available in a number of thicknesses, ranging from 1/4 to 1-1/4 inch thick and also including 3/8, 1/2, 5/8 and 3/4 inch thicknesses, which are the most common sizes. CDX & Struct-1 available. CDX is a great economical choice for construction grade plywood! FSC Certified plywood for green construction. The major difference between them is that marine grade plywood is made of more durable veneers, which will withstand exposure to moisture better than CDX plywood. This CDX plywood is economic so one can easily get it and that also in enough quantities. The letter "X" stands for exposure, which means the plywood is tough enough to withstand a … A more economical choice this plywood allows for knots and other imperfections on both faces. CDX, ACX, & Fire retardant available with chain of custody certificate. Actually, the odd number of veneer layers allow for an even number of glue layers. Technical specification: Length. Used it over 3/4" ply when replacing the subfloor in my house. If you’re in the middle of a project and winter sets in…that’s another matter altogether. 3/8 Cat Ps1-09 Square Structural Douglas Fir Sheathing, Application as 4 x 8. Our plywood calculator can estimate the number of 4′ x 8′ sheets needed for a project. This resistance to weather and dimensional stability after exposure makes CDX a superior choice for roof and wall sheathing, as opposed to the more economical OSB (Oriented Strand Board). These clips, so named due to their shape, connect the edges of adjacent sheets of plywood, halfway between the rafters, helping to ensure that one panel doesn’t bow one way and the next bow the other way. Each layer is made from one piece of wood, so there are no gaps in the middle layers that could weaken the sheet or … Thus, a plywood sheet with a nominal thickness of 3/8 inch is actually 11/32 inch thick. Source: The actual thickness of these plywood sheets will be 1/32 inch less than the nominal size, due to finish sanding of the sheet. Typical size is 4 ft x 8 ft, but other sizes may also be produced. Item #12181 Model #185109 Learn how to layout wainscoting with all panels a consistent size for an even look. The designation of being exterior grade plywood can also mean “Exposure grade 1” which stands for damp-proof plywood used for demanding environments such as underlayments and roof sheeting. 1220 mm. Plywood Prices - OSB, CDX, T&G costs for interior and exterior plywood panels, sheets. When referring to thickness, exterior grade plywood is nominally smaller than the referred to dimension e.g. When CDX plywood is used as roof sheathing, the C side of the plywood is placed up, where it will be covered by roofing felt and then shingles. This added strength means less bowing/flexing in the subfloor. They may even be commonly referred to as plywood, despite being manufactured differently. After screwed down on a 12"x12" grid and vinyl plank flooring over it the top layer of the Show more. APA Rated Sheathing panels are produced as plywood or oriented strand board (OSB). Buy on Beacon Pro+. Plywood is almost always thinner than the nominal measurement due to the fact that most tooling in furniture and cabinet factories and manufacturing facilities can accommodate plywood that is thinner than expected but not thicker than expected. If you have exposed edges, cap them with hardwood. For this reason it is very common to see actual thicknesses on the thinner side and rarely thicker than the nominal measurement. When we compare these two different softwoods, we find that fir has less soft grain than pine. 5. Compared to CDX plywood sheets with the same thickness, these sheets have thinner layers and more of them, making this plywood stronger and denser. It hasn’t been immersed in rosin, like a truly waterproof wood is. Also, having 3/8″ thickness of wood compared to 1/4″ gives more wood for the nails to hold onto. Rated sheathing, also known as CDX in the trade; ... (Panel width and length may vary up to 1/8" to aid with proper installation) Specifications. As the most widely recognized plywood product on the market, CDX plywood is accessible in various thicknesses, going from 1/4 to 1-1/4 inch thick and furthermore including 3/8, 1/2 CDX plywood, 5/8, and 3/4 CDX plywood. From . When making a selection below to narrow your results down, each selection made will reload the page to display the desired results. Another reason for varying plywood thicknesses is a range of manufacturing tolerances. ... Sheathing, CDX Plywood 2440mm x 1220mm" 9000189656. Plywood Alternatives. Item Number 271066. Limited splits, discoloration or sanding defects that don’t affect the plywood’s strength. It is important, when doing a remodeling job, to understand what is currently installed and what that municipality allows. The plywood made of more plies is stronger than the plywood of same thickness but made of less plies. This plywood is made with an exterior grade glue. 23/32 in. There is a mistaken idea that H-clips are there to provide spacing for expansion between the sheets of sheathing. Solid, more knots than A grade, possible minor splits. Email Address Sign Up. per sheet (Inc. VAT) Select thickness. Minimum Plywood Thickness The International Residential Code specifies 3/8-inch plywood for sheathing walls with a standard stud spacing … For most applications the 1/32” difference is not important, but for fine carpentry it may be critical to get grooves and cuts to be precisely the thickness of the plywood. Based upon this grading system, we can see that CDX plywood has one side that is “C” grade and one that is “D” grade. It’s not just plywood, other types of lumber are smaller than the advertised nominal dimensions for this reason as well. The higher grade panels are sanded on both sides and are sometimes referred to as Sanded Plywood or Sanded Panels. Exterior grade plywood, marked with an “X” after the surface grade (CDX plywood means face side is grade C, back side is grade D, and the plywood is intended for exterior use) uses a resin that is more water resistant than interior grade plywood. The term CDX is basically not the name of the plywood grade, but the abbreviation of C-D Exposure 1 plywood. The “C” graded side is the face side, used where it is more visible, and the “D” graded side is the reverse side, usually mounted in a way that hides it. This grade of plywood has many voids in it. This type of plywood is used in commercial building applications to meet with building code regulations for fire suppression and/or safety concerns. It is usually made from fir or pine, just like CDX. This number is known as a span rating. Limited number of patches. Packing crates or shipping large valuables and furniture are often made of CDX plywood, taking advantage of its low cost, high strength and water resistance. CDX plywood is often utilized as roof sheathing or for exterior walls due to its water resistance. Feet and Inches Length Measurement Calculator. Radiant Barrier aluminum backed sheathing -- Improves energy efficiency. 1. CDX Plywood Size, Thickness, and Availability. Weight. Available in 3/8″, 1/2″, 5/8″ and 3/4″ thicknesses. Our board footage calculator can help calculate how many board feet you need if your plywood is sold using that measure. That said, CDX plywood isn’t immune to the slings and arrows of Mother Nature indefinitely. 34.83 kg. 3/4” plywood by its more accurate thickness of 23/32”, 5/8” plywood by its more accurate thickness of 19/32”, 1/2” plywood by its more accurate thickness of 15/32”, 3/8” thick plywood by its more accurate thickness of 11/32”. Providing better information on softwood and hardwood. Item # 271066 . CDX plywood is manufactured, like other types of softwood plywood, of opposing layers of wood veneers, laid at right angles to each other and glued together with resinous glue. There are always an odd number of layers, balancing the sheet, to prevent warping of the panels. Both types of panels swell around the edges as they get wet, but plywood returns nearly to its original thickness as it dries, while OSB swelling is irreversible. Face veneer is practically free from all defects. x 4 ft. x 8 ft. RTD Sheathing Syp - The Home Depot Available Sizes: 4'x8' sheets; 3/8, 1/2, 5/8, 3/4 thickness of Plies in a Plywood. Add and subtract feet, inches, fractions, centimeters, and millimeters with ease. Although considered an exterior plywood, CDX is often utilized as the subfloor for kitchens and bathrooms— especially for floors destined to be finished with ceramic tiles. 2440 mm. You can use other types of boards in place of true plywood. Estimate how many mouldings you need to trim a room using the trim and moulding calculator. Specifications ; Specifications. The veneers are rotary cut from a log. The secret to using CDX plywood for these applications is to first, design your project in such a way as to leave no exposed edges. This leaves the D side facing down, into the attic, where it will most likely be seen. The recommended shed floor plywood thickness is 3/4 inch pressure-treated exterior-grade CDX plywood. Herein, the letters C and D denote the quality of the surfaces (both front and back). Get results in imperial and metric measurements. Although available, it is rare to find plywood where both sides are the same grade. While this may not be allowed by building inspectors in all jurisdictions, it is in many. What is the Actual Thickness of a Sheet of Plywood. The thicker the plywood, the more noticeable depth the gap is between the planks. Therefore, it is designed to handle a limited amount of rainfall, without causing any significant damage to the plywood. Either roof felt or Tyvek house wrap could be used to dry in the exposed wall and roof sheathing. Because the actual thickness may vary measuring the plywood is the only accurate way to determine its thickness. The smoother C side is better for putting roofing felt onto, as splits and holes can cause wear in the felt, leading to failure. For example, 18mm plywood of 15 plies is stronger than 18mm plywood … of Plies will increase 2 plies; 2. Plywood is most often sold in 4′ x 8′ sheets, but may also be available in 4′ x 10′, 4′ x 12′, or 2′ x 4′ sheets. Nominal Thickness. Nominal Width. Lower cost engineered sheet wood products, such as OSB can much more easily be punctured in these applications, limiting the amount of protection they can provide to the goods stored inside. Please note that these are nominal thicknesses. Thickness. This is mostly because void free veneers are used in the making of marine grade plywood, whereas some voids are permissible in the manufacture of marine grade plywood. This additional strength really helps when using CDX plywood as subfloors. Some mistakenly think the "X" stands for "exterior"—which is not true, exactly. While the voids and splits do affect the structural strength of the plywood somewhat, that is calculated into the permissible load for the specific plywood thickness. Plywood is usually sold by the sheet, but in some rare cases it may be sold by the board foot. Learn more about plywood weight for different types, including softwood, hardwood, marine-grade, OSB, MDF, MDO, and particle board. In both cases, we’re talking about conifers, which have needles that they do not lose in the fall. This makes it usable in more visible applications, such as the building of furniture, even though it isn’t a cabinet grade plywood. Width. However, the Universal Building Code states that it is acceptable to use 3/8” thick CDX plywood for sheathing. CDX plywood is the lowest class of plywood and is often used in the construction industry or as a base for other materials. The plywood will provide a stronger shelf than OSB would, with less tendency towards waviness. Exterior sheathing is most often ½” thick (nominal dimension; actually 15/32” measured dimension) for both walls and roofs. Softwood plywood, which includes CDX plywood, is either made of pine or fir. Most plywood is graded based upon the finish of the exterior layers, specifically the amount and type of defects that are allowed in these layers. These were mostly shelving units of one sort or another, but I have also built children’s furniture, such as fire truck bunk beds and animal shaped toy boxes. CDX plywood is much thicker and can be bought for low prices in large volumes. ... CDX plywood should be a minimum of 7/16 inch thick. As CDX plywood is not intended for visible applications, where appearance is important, the lower cost of rotary cutting is advantageous. Plywood is often sold in 1/4“, 1/2“, or 3/4” nominal thicknesses, but the actual thickness is often 1/32” thinner. In most cases, 1”x 4” is enough, as it will support the weight to be put on the shelf.