Types and Grades of Plywood for the Roof

As far as roofing materials go, there are two basic types of boards: standing seam and pressed board. Standing seam roofs are tapered at both ends and stand side-by-side like a row of bricks. This type of roof can only be installed when the roof and the floor are at the same plane. With a pressed board roof, the boards are all the same size and pressed together. This type of roof is usually installed along with a vapor barrier or underlayment to help prevent condensation.

Plywood is a type of wood used to construct roofs, but this is not simply a description of a material, it is a name given to a specific type of timber. A number of different plywoods are available, and each one is designed specifically to suit a particular purpose. The following is a guide to help you choose the right one for your project.

There are a variety of different types of wood for the roof, but the two most common are softwood and hardwood. The two types are distinguished by the grain of the wood, and therefore the strength and durability of the wood. While softwood is generally less durable than hardwood, it is usually more affordable. Hardwood is more expensive, but it has a wider variety of uses, including for roofs and decking.. Read more about a grade plywood and let us know what you think.

Plywood is a typical building material that you may not be aware plays an essential part in the construction of a roof. There are many kinds of plywood, and not all of them are appropriate for structural purposes, so knowing the differences is essential if you’re doing a DIY roof repair to guarantee the roof’s stability and durability. Here you may learn all there is to know about the many types of plywood for roofs.

Plywood is a kind of wood that is used to make furniture.

Plywood is a kind of engineered wood that is constructed from thin sheets of wood bonded together on top of one another. Each sheet of wood will have a grain that runs at a right angle to the preceding layer, providing it more strength. Plywood is made out of at least three sheets of wood, although it is more usual to have up to five.

Plywood is used in roofing for a variety of reasons.

Roofs are constructed from rafters and trusses, which provide the roof’s structure; however, a level deck must be placed on top of the frame, to which the final roof material, such as tiles or felt, may be attached. Plywood is an excellent choice for a roof deck since it is both affordable and long-lasting. Solid wood would be a waste in this case since the roof deck would not be visible after the roof is finished, thus it doesn’t matter how it looks. Plywood has the strength to support the weight of the material that will be placed on top of it, as well as heavy snowfall or ice.

Plywood is water resistant, which is advantageous when used in outdoor applications like roofing. If it does expand due to moisture, it does so uniformly so that the roof’s structure is not compromised. It also dries rapidly, reducing the risk of mold growth and other moisture-related problems.

Plywood is very simple to work with and can be cut to size using circular or handheld saws. The typical sheet size for plywood is four feet by eight feet, which is a good size to deal with while also covering a good amount of roof surface area. Larger sizes are available, although they’re not as popular. Plywood is also available in a variety of thicknesses to accommodate varied loads.

Plywood Types for Roofing

Plywood is divided into two kinds for roofing: structural plywood and ordinary plywood.


Structural plywood is the highest grade of plywood, having a performance certification that ensures it fulfills or exceeds structural construction standards. This kind of plywood is helpful in a variety of circumstances, although it is best utilized in structural applications, as the name suggests. It will be water-resistant, making it ideal for use on a roof where moisture may be a problem.

The kind of glue used to join the layers is the main distinction between structural and ordinary plywood. The layers of wood in structural plywood will be glued together using phenol formaldehyde resin or melamine-urea-formaldehyde. The finest quality of structural plywood is made using phenol formaldehyde resin, which is regarded the best functioning bond. This kind of resin is temperature resistant and prevents moisture from entering the wood.


General plywood is a lower-grade plywood that is ideal for general and interior usage, but it has been known to be used for roofing in certain cases, particularly in arid areas. The layers of general plywood are bonded together with urea formaldehyde resin, which may degrade if exposed to moisture. Extreme temperature fluctuations may also weaken it. The advantage of general plywood is that it is much less costly than structural plywood, which may save you a lot of money if you have a big roof to cover. You may also cover the plywood with waterproof sheeting to assist prevent moisture penetration, although structural plywood designed for outdoor usage is recommended for the greatest performance in wet circumstances.

Plywood Grades for Roofing


Plywood in Grade A is the finest quality. It will be structural plywood with an exceptionally strong bond utilized to glue the layers of wood together, resulting in a plywood that is very resistant to moisture and temperature fluctuations and very robust. Grade A plywood will also be the most visually pleasing, with few or no flaws. This makes it a good choice for interior projects or projects where it will be utilized as a surface, although this isn’t a factor in roofing. Knots in the hardwood sheets may lead to weak areas over time, therefore the absence of defects like knots can assist to guarantee the strength of the plywood.


Grade B plywood is another kind of structural plywood that has few visible flaws. It’s typically constructed using a moisture-resistant adhesive that’s renowned for its toughness. Despite the excellent quality of the plywood, it will be classified as Grade B since the surface will not be as flawless as Grade A plywood. On the surface of the plywood, you may detect some tiny knots or holes, but they will not be many or noticeable.


In comparison to Grade A and Grade B plywood, Grade C plywood will be produced from hardwood layers with greater surface flaws. You may notice some significant aesthetic flaws, like as knots, on this plywood, but it will still be sturdy and appropriate for a broad range of uses, including roofing. Grade C plywood may be utilized for projects where the plywood’s surface will be visible, particularly if it will be painted. You may save money on your project while still getting a nice-looking surface by utilizing Grade C plywood for this purpose. Grade C plywood is considered structural when it comes to roofing and is thus ideal for use on the roof.


The lowest grade of plywood is grade D. This rating is based on the amount of visible flaws in the wood, not on its quality. Although Grade D plywood will show a lot of knots and holes, it will still be sturdy and water-resistant, making it ideal for roofing. Grade D plywood isn’t recommended for applications where the wood will be visible since it may seem unsightly and unfinished. Instead, it’s ideal for structural applications where it’ll be concealed by a more appealing material. Grade D plywood is one of the most cost-effective kinds of plywood, making it an excellent option for lowering construction expenses.



CDX plywood is a popular kind of plywood that is renowned for its durability and low cost. The letter ‘C’ in CDX denotes the grading of one side of the plywood, whereas the letter ‘D’ denotes the grading of the other side. This implies that the grade C sheet on the visible side of the plywood will have some flaws, while the grade D sheet on the below visible side will have more apparent imperfections.

This is an excellent option for jobs where the top layer of plywood will be visible since you can achieve a decent finish while keeping expenses down by using portion of the plywood that is grade D. The X in CDX stands for the kind of adhesive that was used to join the layers together. CDX utilizes a super-strong adhesive that makes the plywood waterproof and resistant to severe temperature fluctuations. This makes it an excellent option for roofing, where it may be exposed to dampness or extreme temperature fluctuations.

CDX plywood is a construction-grade wood that is meant to be used outside. Because of its robustness and cost-effectiveness, it is the most frequently used grade of plywood in roofing.

Roofing Plywood Dimensions

The thickness of plywood used on a roof is determined by the load that the roof must bear. A flat roof will bear a greater load and, as a result, will need a thicker kind of plywood than pitched roofs, which bear a lower load since the weight is distributed more evenly. In most cases, the minimum thickness of plywood utilized in roofing is 38 inches. When the roof rafters are spaced 16 inches apart, this is acceptable for modest loads.

Roofing plywood is most frequently found in thicknesses of 12 inch or 58 inch. These thicknesses are appropriate for normal loads with roof rafters spaced 24 inches apart. Plywood with a 34-inch thickness is best for roofs that must be able to withstand higher weights.

Gaining access to a mobile phone while in prison is difficult. Most are locked up tight, and even if they were not, most in prison would not be able to access a phone in their cell even if they wanted to. This post will focus on the types and grades of plywood used in making the roof of the prison cells.. Read more about types of plywood and let us know what you think.

Frequently Asked Questions

What grade of plywood is used for roofing?

The grade of plywood used to build a roof is typically determined by the thickness of the material. For example, if you are building a roof that will be 4 inches thick, you would use a 2×4 or 3/4 inch plywood.

What are the 4 grades of plywood?

Plywood is graded according to the number of plies. The more plies, the higher the grade.

What are the 5 grades of plywood?

Plywood is graded according to the number of plies it has. The more plies, the thicker and stronger the plywood will be.

This article broadly covered the following related topics:

  • types of plywood
  • plywood
  • plywood types and grades
  • plywood grades chart
  • home depot plywood
You May Also Like