Plywood is a very versatile building material, one that can be used for roofing, floors, walls, and everything in between. That being said, there are many types of plywood out there, and this is true in more ways than one.
There are in fact different types, grades, and ratings of plywood, each of which we are here to talk about in detail today.
17 Types of Plywood
Let’s get right to it and talk about all of the different types of plywood that you might find at your local lumber store.
Softwood Plywood
As the name of this type of plywood suggests, it is made out of various softwoods, ones such as Hem-fir, Douglas Fir, and SPF, plus many more.
Although this plywood is made with softwood, it is actually very strong and has great structural integrity. For this reason, softwood plywood is often used for roof sheathing, exterior frame sheathing, subflooring and temporary flooring, and other such purposes.
Hardwood Plywood
Hardwood plywood on the other hand is made out of various hardwood trees including oak, maple, birch, walnut, and others. Here you will usually find quite a few layers, up to seven, but that said, hardwood plywood can be quite thin, and because the wood is very hard, it also has great structural integrity.
Hardwood plywood is often used in the making of musical instruments, sporting goods, packing cases and boxes, and, primarily for furniture making. Due to its appearance, it is also very easy to finish with a good coat of paint, varnish, or lacquer.
Marine Plywood
If you are building outdoor structures such as large sheds, gazebos, patio tables, planters, and benches, then a good choice to consider would be marine plywood. As the name suggests, it is ideal for applications where a lot of moisture will be involved, but that said, it does need to be treated with water preservatives for the full effect, or else it may mold or warp over time.
This type of plywood generally features a high grade, so it’s quite strong, yet it is also free of knots and holes, and therefore it looks nice too.
Aircraft Plywood
When it comes to super strong, durable, and resistant plywood, aircraft plywood is definitely at the top of the list. This is some of the highest-grade plywood you can get, and as the name of it suggests, one of its primary applications is the manufacturing of aircraft.
What is interesting to note is that this extremely durable plywood, often made of the highest quality hardwoods like mahogany, is actually also among the lightest types of plywood out there and is therefore ideal for a very wide variety of applications. Just keep in mind that aircraft plywood is expensive, very much so.
Interior Plywood
If you are doing basic flooring, walls, or making small pieces of furniture for indoor use, then interior plywood is the way to go. This type of plywood is a fairly decent type of plywood, one that is quite strong and also fairly good-looking, which does make it ideal for various weight-bearing applications, such as for flooring.
That said, this type of plywood is not water-resistant, and should therefore not be used for kitchens, bathrooms, or other areas that frequently get wet.
Exterior Plywood
If you are building anything outdoors, a good choice to go with is exterior plywood. This is the perfect kind of plywood for exterior walls, roofs, patio chairs and tables, and more.
The reason for this is because exterior plywood features very strong and high-quality woods that are glued together in many layers using waterproof glue. This stuff is also highly wind and temperature resistant. No, it’s not the cheapest kind of plywood out there, but it is very good.
Structural Plywood
If you need to build floors, walls, shelves, benches, and more, anything that needs a ton of strength and can hold a lot of weight, then structural plywood is the way to go.
Although this type of plywood does have incredible strength, it is filled with holes and knots and is therefore not the best in terms of appearance. Moreover, structural plywood is not really resistant to water either, so it should not be used for exterior purposes.
Lumber Core Plywood
Lumber core plywood is usually made of just three layers. The big difference here is that the exterior layer of this plywood being very thin veneers made out of hardwood, with the interior also being made out of hardwood strips that are glued together. This is a very strong type of plywood that is very resistant to cracking, and it has a great ability to hold screws in place.
As such, it’s a good option if you are building something intricate that will require lots of screwing.
Overlaid Plywood
Overlaid plywood is very similar to the traditional kind, with the difference being that it has a finished and overlaid face which looks very nice and aesthetically pleasing.
Although it does look very nice, this overlaid finish actually has the main benefit of being very scratch-resistant and waterproof. You can get this type of plywood in both high and medium density, with the high-density option having more resin, thus making it more expensive.
Subfloor Plywood
As the name of this type of plywood suggests, it has one main use, which is in the making of subflooring. Now, it may not look the nicest, but because a real floor will be put overtop, appearances are not overly important.
The important part is that subfloor plywood can handle a lot of weight and is also extremely resistant to moisture.
Veneer Core Plywood
This is the most basic type of plywood out there, and one of the most affordable kinds too.
It is made with many layers of wood bonded together.
Exterior Sheathing Plywood
This is a very special type of plywood, and as the name suggests, it has one specific application, exterior sheathing.
When it comes to lateral bracing and building exteriors, it’s a great option to consider. It can come in various ratings, but generally speaking, it is structurally sound and somewhat resistant to wind and moisture.
MDF Core Plywood
This type of plywood is made by gluing either hardwood or softwood to an interior layer of MDF or multi-density fiber (a type of engineered wood). This is a fairly basic type of plywood, and it’s affordable too. It’s ideal for simple purposes such as door making. It is stable, has a consistent thickness, and is quite versatile too.
That said, you probably don’t want to use it for exterior applications.
ApplePly
OK, so this is actually a brand name of plywood, but it is so popular that it more or less qualifies as its own type.
This is a high-end veneer core plywood that is designed to look nice. It’s ideal for indoor applications such as shelving, building drawers, and other such things.
Decorative Plywood
Decorative plywood features a high grade. It is designed to be free of imperfections. The main point of it is to look very nice so you can add a layer of it onto the outside of a piece. It could be used for interior walls, for cabinets, and for other such things. It’s smooth and it can be painted.
That said, it’s generally not overly moisture-resistant, so it’s best used for indoor purposes.
Tropical Plywood
This is a special type of plywood, one that is known for being much stronger than softwood plywood, but also much cheaper than hardwood plywood. As the name suggests, this type of plywood is made out of tropical lumber. It comes from Asia but is also produced in South American and African countries.
Overall, this type of plywood has a very high level of quality. It is very strong, dense, and often very resistant to water without much special treatment being required.
Flexible Plywood
This is the final type of plywood we want to look at today, and as you can tell by the name of it, its main benefit is that it is flexible. It is designed to be bent and to make curved structures. It’s very thin, yet also strong and springy.
Types of Ply
The next thing that you need to know about plywood is that it comes in various plies, or in other words, it can be made out of various numbers of layers. Generally speaking, you can find 3-ply, 5-ply, and 7-ply (usually known as multi-ply). Let’s take a look at all three to see what you are getting into.
On a side note, the three options we are about to talk about, while they are the most common, technically are not the only ones, as plywood, in special cases, can have up to 21 layers.
3-Ply
If you need a very common and affordable type of plywood, then 3-ply is the way to go. As the name suggests, this is the thinnest type of plywood with just three layers. It’s usually between two and three millimeters thick.
This is a more decorative kind of plywood, mainly because its thin design means that it looks very nice and is ideal for a variety of tasks such as basic flooring, furniture, small shelves, and more. That said, because it is quite thin, it is not the best option for heavy weight-bearing applications.
5-Ply
This type of plywood consists of five layers and can be around 4 to 4.5 millimeters in thickness. It may still look very nice and feature a high grade, so it can be used for interior purposes where the aesthetics are important.
That said, 5-ply plywood is relatively thick, and therefore also quite durable, plus it is often made with waterproof glue, thus also making it ideal for outdoor purposes. It’s a versatile type of plywood that can be used indoors and outdoors, for everything but permanent structures that are meant to last for a long time.
Multi- or 7-Ply
This is the thickest common type of plywood out there, and as the name suggests, it is usually made out of seven layers, yet, multi-ply may also indicate that the plywood has more than seven layers. This stuff is not the best for furniture or anything that needs to look even very attractive.
However, it is also very strong, stable, and structurally sound, which is why it is perfect for creating frames, roofing, exterior structures, and more.
Plywood Ratings
All plywood has a special rating that indicates what it is best suited for. Specifically, these ratings indicate whether or not the plywood is ideal for outdoor use, particularly in terms of waterproofing, but there is more to it than that. Let’s take a look at the different plywood ratings and what they mean.
Exterior
This is the best type of plywood to use for outdoor purposes. The reason for this is because it is made with waterproof glue, thus making exterior plywood waterproof. It’s ideal for permanent structures that are meant to last for years to come.
Even when using this type, though, you will likely want to add an extra layer of waterproofing.
Interior
On the other hand, we have interior plywood, which is not made with waterproof glue. As the name implies, interior plywood is only ideal for indoor purposes, and should ideally never be exposed to moisture.
Exposure 1
This plywood rating indicates that the plywood panels have been waterproofed to a certain extent. This stuff can resist a good deal of moisture and is suitable for short-term exposure to moisture while construction is taking place. However, it should not be used for permanent structures that will be exposed to moisture over the long run.
Exposure 2
Exposure 2 plywood panels are made with glue that is partially waterproof, or in other words, resistant to very small amounts of moisture. Yes, it can withstand small amounts of moisture, but not much, and is, therefore, best used for interior applications.
Structural 1
This plywood rating indicates that the plywood is ideal for building large structures where earthquake-proofing measures are required. Flexibility is a key factor here.
Plywood Grades
What is also important to know about plywood is that it comes in various grades ranging from A to D, with A being the highest. Moreover, every piece of plywood has either two or three letters which indicate the grade.
For example, this could be AC, with the first letter signifying the grade of the face of the plywood, and the second letter indicating what the grade of the backside is. Some may also include an X at the end, which indicates that the plywood is suitable for outdoor use. Let’s take a look at the different plywood grades right now.
Grade A
This is generally the highest grade of plywood that you can get, and it indicates that the plywood is free or virtually free of all defects. It has a smooth and sanded surface, it looks nice, it is quite strong, and it has no knots, holes, or any parts that have been filled.
It’s a good choice to consider for doors, cabinets, and other pieces of furniture where appearance is paramount. This grade of plywood is meant to be seen, and although it is not designed to be covered by other layers, it may be painted or stained for appearance’s sake.
Grade B
This is the next level down from grade A, and it is also very smooth and sanded, but the face of this plywood may have a couple of minor defects, such as small knots and holes that have been patched. It does still look fairly nice and it does have great properties, but due to a few minor defects, it does cost less than grade A plywood.
Grade C
Grade C plywood is much more affordable than either of the others discussed today, as it is not smooth or sanded and may have knots up to 1.5 inches wide, along with large holes that have been filled or patched. Whatever the case may be, it doesn’t look all that nice, which is why it is best used for applications such as subflooring, where it won’t be seen.
Grade D
Finally, we have grade D plywood, which is not smooth or sanded, it may have knots up to 2.5 inches wide, and very large sections that have been filled. It’s still quite strong and ideal for various structural uses, but it certainly does not look pleasing to the eye.
Summary
The bottom line here is that choosing the right type, grade, rating, and the right amount of layers is very important when selecting plywood for specific applications. As the next step, you might want to learn more about different uses for plywood.
Take your time and choose wisely!